My Mars Science Fiction Story Now Free on the Web

As some of you know, I have begun writing science fiction stories (based on ideas from astronomy) in recent years and two of them have now been published.

The first story (“The Cave in Arsia Mons”) was published in a small-press anthology of Mars stories entitled “Building Red: Mission Mars,” and deals with a surprising discovery made in a cave on the side of one of the giant volcanoes on the red planet.

The publisher has now given me permission to put the story on-line free and it can be found at: https://www.researchgate.net/publication/282914928_The_Cave_in_Arsia_Mons
If you click on the blue “download” button just above and to the right of the title, you get a PDF file with the story and a bit about the actual discovery of martian caves.

My second story (“Supernova Rhythm”) is just being published in an anthology entitled “Science Fiction by Scientists,” edited by astronomer Mike Brotherton, and published by Springer. It concerns an advanced civilization out there that can play music using exploding stars:
http://www.springer.com/us/book/9783319411019 or
https://www.amazon.com/Science-Fiction-Scienti…/…/3319411012

When I retire from teaching at Foothill College in June 2017, I am looking forward to spending more time writing science fiction stories like this.  For my listing of a wide range of science fiction stories with good astronomy, see: http://www.astrosociety.org/scifi 

A Hidden Baby Galaxy in our Cosmic Neighborhood

An international team of astronomers, led by researchers at Japan’s Tohoku University, has just reported finding the faintest satellite galaxy ever seen orbiting our home galaxy, the Milky Way.  All stars are born in great islands or groupings of stars called galaxies.

Big galaxies like the Milky Way are surrounded by smaller “baby galaxies” (or satellite galaxies), some of which collide with it over cosmic times.  About 50 such galaxies are currently known to orbit our Milky Way – with the two “Magellanic Clouds” (discovered by Ferdinand Magellan’s crew) being the most famous of them.

Because many of the smallest galaxies are very faint, they are hard for us to make out.  Remember, we are inside the Milky Way, and so (as we try to look outwards) we always have to observe through the stars and star clusters of our own galaxy.  The faint baby galaxies can be hard to tell apart from clusters or groups of stars in the Milky Way itself. (This is why it’s hard to get a good photo of the Milky Way; we are inside it and so it’s like trying to take a selfie from inside your kidney.  The view is not so clear.)

Still, using the giant Subaru telescope (whose mirror is more than 24 feet wide), the team was able to find the faintest baby galaxy ever found, which is being called Virgo I (since we see it in the constellation of Virgo.)  At an estimated distance of 280,000 lightyears from us, Virgo I was much fainter than earlier surveys for our neighbor galaxies were able to reveal.

The whole Virgo I “dwarf galaxy” is only about 248 lightyears wide.  Compare that to the 100,000 lightyear diameter of the Milky Way! The Magellanic Clouds are estimated to be 7,000 and 14,000 light across.  So you can see that Virgo I really is just a baby. See the tiny smudge it makes on our accompanying image.

But if one such baby galaxy has escaped our notice until now, chances are many others like it may also be out there.  Some of our theories predict that major galaxies like the Milky Way should be surrounded by many more dwarf galaxies that we have seen so far.  Virgo I leads astronomers to think that more may be out there -- just waiting for bigger telescopes and more observations before they are discovered. 

Enjoy Sunday and Monday's "Supermoon" But Don't Fall for the Hype!

You may read stories in the media about Sunday evening’s or Monday morning’s full moon being a “supermoon.” And it is true that – by a slight amount – the full moon just before Monday’s sunrise will be the closest, brightest, and largest-looking full moon since 1948.

But the average person won’t notice much difference between this “supermoon” and an ordinary full moon. Clouds, smog, and human lights turn out to have a much greater effect on how bright a full moon looks to us. Still, if you look carefully under dark skies, you might convince yourself that the full Moon Sunday night and Monday before dawn looks a bit bigger and brighter than usual.

“Supermoon” is not an astronomical term. It was suggested by an astrologer and suddenly became popular in the media (who always favor superlatives) in 2011. We astronomers have been stuck with it ever since.

Why are some full moons bigger and brighter than others? It’s because the Moon’s orbit around us is not a perfect circle, but on oval shape called an ellipse. That means sometimes the Moon is a bit closer to us and sometimes it’s a bit further away. If a full moon happens just when the Moon is closer, we get a bigger and brighter looking full moon. The more precisely the closest moon and the full moon coincide, the better the super effect. Nov. 14th, the moon is full at 5:52 am Pacific time, while the moon is closest at 3:23 am. That’s a pretty close coincidence.

Does the “supermoon” have any significant effect on planet Earth. You may read predictions that there will be much greater tides or even earthquakes Monday morning. Don’t believe it! We have slightly stronger tides every time the Sun, Earth and Moon are lined up (which they are at every full moon). But the only time the supermoon will show itself in a significantly stronger effect on the shore is if we happen to be in the middle of a huge storm. And the Sun and Moon have no effect on earthquakes, which happen deep inside the Earth.

So if you happen to glance at the full Moon Sunday evening or Monday morning, enjoy the knowledge that the Moon is a bit closer to you. You may even howl at the Moon if the candidate of your choice didn’t get chosen in our recent elections. But don’t add the “supermoon” to your list of things worth worrying about.

(Photo of the Lick Observatory with the Moon behind it by Rick Baldridge of the Peninsula Astronomical Society.  This was taken with a special lens to enlarge both the observatory and the Moon.)

Water Worlds in the Solar System

There is new evidence for the existence of liquid water in the cold outer regions of our solar system. Astronomers using the Hubble Telescope see plumes of water erupting from the surface of Jupiter’s moon Europa, and measurements of Saturn’s little moon Dione indicate that it must have a substantial layer of liquid water deep underground.

In recent years, more and more evidence has accumulated that liquid water exists among the moons of the giant planets. We have known for a while that there is likely to be an underground ocean of water beneath the icy crust of Jupiter’s moon Europa, and perhaps also under the surface of its moon Ganymede (the largest moon in the solar system.)

Then the Cassini mission found great geysers of salt water emerging from the icy cracks on Saturn’s moon Enceladus, a world much smaller than the Jupiter moons we just discussed. The big deal here is not that there is water, since water ice makes up a large part of many of the solid worlds in the outer solar system. The big discovery is that, even in those icy realms, enough heat can be generated inside these moons to have oceans of liquid water.

The Hubble work is the second report of plumes coming out of cracks in the ice of Europa. Earlier work, also done with the Hubble, also hinted at such plumes, but now astronomers have observed them in ultraviolet light as Europa was crossing the face of Jupiter. Our top image shows you what was observed, with a visible-light picture of Europa photoshopped in to show you what the moon looks like. A short NASA movie explaining the discovery can be seen at:
https://www.youtube.com/watch?v=4QJS9LcB66g

The work on Dione was more indirect. This moon of Saturn’s is about 700 mi across, more than twice as big as Enceladus. The presence of water was suggested by measurement of the gravity of Dione, as the Cassini spacecraft flew by it. The gravity measurements fit with the presence of a water layer deep inside the moon, perhaps 60 mi beneath the surface.

(The bottom image shows a very detailed image of Dione's surface from the Cassini spacecraft.  You see many icy cracks and fractures, whose sides show as white cliffs.)

Something must heat the buried “oceans” in these moons to keep them liquid. In some cases, it is a tug of war between the gravity of the mother planet on one side, and a large moon on the other. Or it may be some kind of rocking back and forth, which scientists call “libration”. Whatever allows liquid water layers to exist out there, the fact that they do makes them an interesting place to look for the beginnings of life.

Water Worlds in the Solar System

There is new evidence for the existence of liquid water in the cold outer regions of our solar system. Astronomers using the Hubble Telescope see a plume of water erupting from the surface of Jupiter’s moon Europa, and measurements of Saturn’s little moon Dione indicate that it must have a substantial layer of liquid water deep underground.

In recent years, more and more evidence has accumulated that liquid water exists among the moons of the giant planets. We have known for a while that there is likely to be an underground ocean of water beneath the icy crust of Jupiter’s moon Europa, and perhaps also under the surface of its moon Ganymede (the largest moon in the solar system.)

Then the Cassini mission found great geysers of salt water emerging from the icy cracks on Saturn’s moon Enceladus, a world much smaller than the Jupiter moons we just discussed. The big deal here is not that there is water, since water ice makes up a large part of many of the solid worlds in the outer solar system. The big discovery is that, even in those icy realms, enough heat can be generated inside these moons to have oceans of liquid water.

The Hubble work is the second report of plumes coming out of cracks in the ice of Europa. Earlier work, also done with the Hubble, also hinted at such plumes, but now astronomers have observed them in ultraviolet light as Europa was crossing the face of Jupiter. Our top image shows you what was observed, with a visible-light picture of Europa photoshopped in to show you what the moon looks like. A short NASA movie explaining the discovery can be seen at:
https://www.youtube.com/watch?v=4QJS9LcB66g

The work on Dione was more indirect. This moon of Saturn’s is about 700 mi across, more than twice as big as Enceladus. The presence of water was suggested by measurement of the gravity of Dione, as the Cassini spacecraft flew by it. The gravity measurements fit with the presence of a water layer deep inside the moon, perhaps 60 mi beneath the surface.

(The bottom image shows a very detailed image of Dione's surface from the Cassini spacecraft.  You see many icy cracks and fractures, whose sides show as white cliffs.)

Something must heat the buried “oceans” in these moons to keep them liquid. In some cases, it is a tug of war between the gravity of the mother planet on one side, and a large moon on the other. Or it may be some kind of rocking back and forth, which scientists call “libration”. Whatever allows liquid water layers to exist out there, the fact that they do makes them an interesting place to look for the beginnings of life.

Ringshine on the Night Side of Saturn

A spectacular new image of the night side of Saturn and its shining rings in sunlight was released recently by the Cassini mission. You can also see the shadow Saturn casts on its rings.

This August 2016 view shows the complex structure of the planet's rings clearly. You can see the two gaps in the rings, one wider and one narrower (in the outer part of the outer ring.) Close-ups have revealed fainter rings and moons in the gaps, so they are not really as empty as they might seem.

The sunlight reflected from the rings keeps the night side of Saturn from being as dark as it could be, much as moonshine keeps the nights on Earth from being completely dark. One scientist calculated that if you could float in the upper cloud layers of Saturn (which has no solid surface), you could read an astronomy book by ringshine.

Look at the complexity of Saturn's rings -- ringlet after ringlet can be seen in each main ring. And each ringlet consists of millions of icy chunks, all orbiting together around the equator of Saturn. The main composition of these icy chunks is water -- making the rings a significant reservoir of water for future explorers. (Although two of Saturn's moons, Enceladus and Dione, are now thought to have liquid oceans of water under their icy crusts. Perhaps we can siphon some of that instead of melting ring chunks.)

The image was taken from a distance of 870,000 miles (which seems far, but Saturn was about 850 million miles from Earth at that time, so Cassini definitely had the better view.)

A Great New Image of Saturn

NASA has recently released a spectacular new image of the planet Saturn, seen when it's summer in the Northern Hemisphere. (A year on Saturn is about 30 Earth years, so each season there lasts about 7.5 of our years! Saying goodbye for summer vacation is a big deal there.)

The rings are seen in fine detail with the shadow of the planet toward the left side. The mysterious hexagon-shaped storm at the north pole is also clearly visible. You are seeing Saturn from a distance of about 1.9 million miles.

The image was taken with the Cassini spacecraft that has orbited Saturn and shown us the planet, its rings, and its fantastic moons since 2004.

Enjoy. (Click on the image to see it bigger.)

Planet Discovered Around the Nearest Star

Astronomers at the European Southern Observatory are announcing today that they have found an Earth-sized planet orbiting the nearest star to the Sun, Proxima Centauri.  The star is only 4.2 light years away (which is roughly 25 thousand billion miles – that’s close for astronomers!)

The newly found planet takes 11 days to orbit its reddish star (compare that to Mercury, the closest planet in OUR solar system, which takes 88 days to go around the Sun.)   You might think that a planet that takes only a week and a half to orbit its star must be outrageously hot, but the difference is that Proxima Centauri is a much fainter and cooler star than the Sun.  So the planet could be in the star's habitable zone (liquid water may possibly exist on its surface.)

We found this planet, as we have many others, not by getting a picture of it, but by measuring the pull of the planet on the star.  As the planet circles the star, from one side of it to the other, the planet’s gravity, small as it is, makes the star wiggle just a little bit.  And it’s this wiggling of the star that we can detect from Earth and use it to estimate the mass (gravity) of the planet.

This method can only tell us the minimum mass that the planet must have, and that turns out to be 1.3 times the mass of the Earth. (The wiggle, by the way, only changes the motion of the star by about 3 miles per hour, toward us and then away from us.  That’s a tiny change, but modern instruments are able to make out changes in speed that small.)

A planet with that low a mass is most likely a solid rocky planet, like ours.  Being so much in the gravity embrace of the star, the planet may have one side permanently pointed toward it, much like our Moon has one side permanently pointed toward the Earth as it goes around us. The Proxima Centauri planet would then also rotate in 11 days, making its day and its year the same length!   That’s weird to think about.

The fastest planetary probe we have built so far would take something like 80,000 years to get to Proxima Centauri.   It’s hard to get graduate students to volunteer for that kind of trip!  But, as you may have heard, Yuri Milner, the Russian-American billionaire physicst, has, earlier this year, pledged a hundred million dollars for a research effort to develop a mini-probe, smaller than the smallest cell phone, yet with working instruments, that could ride powerful laser beams and get to the nearest star system in only 20 to 25 years.

Clearly, Project Breakthrough Starshot, as it’s called, will now focus on Proxima Centauri, the nearest of the three stars in the closest star system.  Bets have been on one of the other two stars (called Alpha Centauri, after the brightest in the pair) to have planets, but the first discovery belongs to Proxima.  What an exciting time to be alive.

Above is an artist's conception of what Proxima would look like from the planet's vantage point, and below is a diagram with key characteristics of the Proxima system compared to our own.

Happy One Year Pre-Anniversary of the All-American Eclipse of the Sun

August 21 is exactly one year before the 2017 eclipse of the Sun which will sweep across one country and one country only -- the US. On a Monday morning (Aug. 21, 2017) this "All-American" eclipse (as it's being called) will begin on a beach in Oregon and cross the country diagonally to end in the afternoon on a beach in South Carolina.  See the map below.

The eclipse will be total (moon covering the Sun completely) only in a path about 60 miles wide and we expect huge crowds and traffic jams in that zone. The rest of North America (500 million people) will see a partial eclipse, with a big bite taken out of the Sun. Special eclipse glasses or ways of projecting an image of the Sun will be needed to see the partial eclipse safely.

The full story,in everyday language, with a map and times for major cities, and safe viewing guidance, can be found in a free 8-page excerpt from a book, called Solar Science, that Dennis Schatz and I wrote for teachers. It is at: http://bit.ly/2bkGSvA

There is a national committee that I serve on trying to arrange a good experience with the eclipse for as many people as possible. Wish us luck! Dennis and i are also working with science teachers, libraries, and science and nature museums to become centers of eclipse information for their communities.

I'll say more about preparations for the eclipse on this page as the year goes on. But for now, you may want to note the date and if you have friends or relatives in the total eclipse zone, be extra nice to them starting now.

And thanks to Prof. Tyler Nordgren of the University of the Redlands for permission to use his cool poster.

Map of the 2017 Total Eclipse Path

For those of you who are teachers, or who know a teacher, we will be doing a webinar on how to prepare yourself and your students for the eclipse.  For more see:

http://bit.ly/2bbAwfo

A Sparkling Cluster of Stars from the Hubble

Here is a beautiful new image from the Hubble Space Telescope, showing a young cluster of stars called Trumpler 14.

Located about 8,000 light years away in the constellation of Carina, this grouping of hot bright stars formed only recently from a great cloud of cosmic raw material, called the Carina Nebula. It is one of the great ideas that we now know about how stars live that the more massive a star, the brighter it shines, and the shorter its life-span will be before it "burns out." Superstars die first, is the general rule.

Because Trumpler 14 formed only about 500,000 years ago (which is a very short time on the cosmic scale), this group still includes a lot of bright superstars, which dominate our image.

Robert Trumpler (1886-1956) was a Berkeley astronomer, who compiled a very useful list of star clusters (places where dozens to thousands of stars are born together.) An annual award at the Astronomical Society of the Pacific, honoring the best PhD thesis in astronomy in North America, is named in his honor.

In our picture, you can see a jewel-like display of bright stars in front of the glowing gas and dust of the nebula. The stars in this cluster are one ten thousandth the age of our Sun. Mere babies, really!

Click on the photo to enlarge it and see it even better.  

Perseid Meteor Shower May Show an Outburst

This Thursday and Friday, there will be one of the best annual meteor showers you and your family can watch -– the Perseids.    And some experts are even predicting that there might be a meteor “outburst” this year –- where the number of shooting stars increases beyond the usual rates.

This is a complicated year for watching the Perseid meteor shower, because the evening sky has a roughly half-lit-up moon in it, making it more difficult to catch the faint “shooting stars.”  So if you can wait until the Moon sets (between midnight and 1 am), you should have better viewing in the pre-dawn darkness.   (That’s great advice for people on camping trip and insomniacs, but probably not useful for those who have to get up for work.)

The best night is the evening of Thursday, Aug. 11 and morning of Friday, Aug. 12^th, although there could be significantly more meteors in the sky on the night before and the night after too.  Meteors or “shooting stars” (which have nothing to do with stars) are pieces of cosmic dust and dirt hitting the Earth’s atmosphere at high speed and making a flash of light.  These flashes could happen anywhere in the sky, so it’s best to view the shower from a wide-open place.  See the list at the end for viewing suggestions.

The Perseid meteors are cosmic “garbage” left over from a regularly returning comet, called Swift-Tuttle (after the two astronomers who first discovered it).  The comet itself returns to the inner solar system every 130 years or so; it was last here in 1992.  During each pass, it leaves dirt and dust behind and it is this series of long dirt and dust streams that we encounter every August.  Some scientists who study comets and meteors are predicting that we might briefly encounter an especially crowded part of the debris stream this time.

Each flash you see is a bit of material from the comet hitting the Earth’s atmosphere and getting heated up (and heating up the air around it) as it speeds through our thick atmosphere.  Both the super-heated dust and dirt and the heated air contribute to the visible light we observe.  Since comets are left-overs from the early days of our solar system, you can tell yourself (or your kids) that each flash of light is the “last gasp” of a bit of cosmic material that formed some 5 billion years ago.

EIGHT HINTS FOR “TAKING A METEOR SHOWER”

1. Get away from city lights and find a location that’s relatively dark

2. If it’s significantly foggy or cloudy, you’re out of luck

3. Your location should allow you to see as much of the dome of the sky as possible

4. Allow time for your eyes to get adapted to the dark (at least 10 -15 minutes)

5. Don’t use a telescope or binoculars – they restrict your view (so you don’t have to be part of the 1% with fancy equipment to see the shower; this is a show for the 99%!)

6. Dress warm – it can get cooler at night even in August (and don’t forget the insect repellent while you are outside)

7. Be patient (it’s not fireworks): keep looking up & around & you’ll see flashes of light

8. Take someone with you with whom you like to spend time in the dark!

A Tight Little Planet System, Dancing to the Tune of Gravity

Careful measurements using information from the Kepler planet-hunting spacecraft has allowed astronomers to figure out one of the tightest and most synchronized planet systems ever found.

Kepler 80 is a dim star in the constellation of Cygnus the swan, 1100 light years away, that has five planets orbiting it. That by itself is not unusual -- astronomers have now discovered a number of stars with 7, 6, or 5 planets around them and more are likely to be discovered as time goes by. What IS unusual is how tightly these five planets all hug their star.

The five planets take one, three, four, seven and nine earth days to orbit the star. (Think about that, their year is 1, 3, 4, 7, or 9 DAYS! If you lived on the inner planet, you would be 365 of its years old after one Earth year had gone by.)

Even more interesting, the outer 4 planets have orbits that are synchronized -- they are in tune, you might say. They return to the same arrangement of their positions around their star every 27 days. This is called a gravitational resonance and it's something gravity prefers to do when bodies can exchange energy.

Think of gravity like your uncle who is careful with his money -- they both prefer arrangements that are cheap! For example, gravity, when it can, tries to make bodies round, because then the pull on every point on the surface is the same -- which is the arrangement that takes the least energy.

When objects in space move around or with each other in a synchronized way, where one orbit is related to the other with numbers like 1 to 2 or 2 to 3, this requires less energy too. Pluto, for example, shows an extreme example of such resonances: Pluto takes 6.4 Earth days to spin and Pluto's big moon Charon takes 6.4 days to orbit the dwarf planet. So Pluto's day and month are the same length. Charon also takes 6.4 days to spin, so we have a 1 to 1 to 1 resonance of these motions.

Calculations show that the planets dancing in resonance around Kepler 80 are rocky world like our own Earth, although at least some of its planets are 4 to 6 times Earth's size. Imagine these giant Earths whipping around that little star in Cygnus in 1 to 9 days, year in and year out, lining up every 27 days in a kind of cosmic dance. Nature seems to permit so many odd and wonderful line-ups of planets out there -- science fiction is having trouble catching up to science fact.

(Just for comparison, the innermost planet in our own planetary system, Mercury, takes 88 days to orbit the Sun, and it is much smaller than Earth. So we have no large planets tightly hugging our star -- but a number of other stars besides Kepler 80 show such tight arrangements.)

Our Astronomy Lecture Series Has a Million Views on YouTube

As regular readers may know, I have the pleasure of organizing and moderating a series of public talks at my college called the Silicon Valley Astronomy Lectures. Thanks to a generous anonymous donor, we are able to record, edit, and publish each talk on YouTube (now in High Definition). Yesterday, the counter at our YouTube channel passed one million views of the lectures from around the world!

Recent speakers have included Carolyn Porco, imaging team leader for the Cassini mission to Saturn; Robert Kirshner of Harvard and Alex Filippenko of Berkeley, both members of the teams that discovered, to everyone’s surprise, that the expansion of the universe is accelerating; Caleb Scharf of Columbia, explaining his book, "The Copernicus Complex," about humanity’s place in the cosmos; astronaut Ed Lu about discovering asteroids that threaten the Earth; and NASA’s Jeff Moore, from the New Horizons science team, explaining what we have discovered about Pluto this year.

Older lectures include Frank Drake explaining his current thinking about the Drake equation, Michael Brown (who discovered many of the Pluto-like dwarf planets out there) discussing "How I Killed Pluto...," Leonard Susskind on his battle with Stephen Hawking over black holes, and Helen Quinn on the mysteries of antimatter.

You can enjoy all the videos, free of charge or advertising, at:http://www.youtube.com/svastronomylectures

Even an astronomer like me, used to big numbers, is kind of impressed by a million views! I'm glad there are so many fans of astronomy out there. Or maybe, when people think about what's happening in the country and in the world right now, their thought have to escape into the larger universe to stay sane!

Big Day for Astronomy Discoveries: Gravity Waves, Alcohol and Tatooine 9

The national organization of professional astronomers (the American Astronomical Society) is meeting in San Diego this week, and there is BIG news from the meeting: More gravity waves, wood alcohol in space, and a big Tatooine-like planet.

Scientists working with LIGO (the Laser Interferometer Gravitational-Wave Observatory) have announced their second discovery of gravity waves. (The first was announced in February.) Once again they observed two giant black holes coming closer and closer and then merging into a bigger black hole. In the merger, some of the mass in the system is converted to energy, and comes out as the waves of gravitational energy Einstein predicted about 100 years ago.

The black holes that merged were 14 and 8 times as massive as our Sun, somewhat smaller than those in the first discovery. Scientists estimate that the black hole that came out of the merger had as much stuff as 21 Sun. This means an entire Sun's worth of mass was converted to energy -- explaining why we could detect the gravity waves, even though such waves are much, much weaker than other waves we know and love, like radio or x-rays.

In the second discovery, a team of astronomers from around the world used the giant ALMA array of radio telescopes in Chile to measure the presence of alcohol in the planet forming disk of a young star 170 light years away. Alas, the kind of alcohol they found is what we call "wood alcohol" or methanol, not the drinkable version. Still, this is the first detection of one of the complex building blocks of life in the region around a newly formed star that is making planets as we observe it.

We have found many of the basic chemical building blocks of life in comets, in chunks of rock that fall from space, and especially in the great clouds of raw material (gas and dust) from which new stars form. But this is the first time we see the "fingerprints" of such a molecule in the flat disk around a star which is the nursery from which planets like Earth and Jupiter emerge. The name of the star is TW Hydrae in case you want to search for more information. (Our image shows an artist's impression of the disk and the molecules of methanol.)

And, finally, in a discovery that is bound to warm the hearts of Star Wars fans everywhere, astronomers have announced the discovery of the ninth, the largest, and the furthest planet orbiting two stars. Such a world could have two suns in the sky at the same time -- just like Tatooine, Luke Skywalker's home planet.

The newly discovered planet, called by its catalog number Kepler
1647b, is about the size of Jupiter and takes three years to orbit its star. The star system is about the same age as our own. And most intriguingly, the new planet orbits in the "habitable zone" of the double star -- meaning that the temperature in the planet's neighborhood would be comfortable for water and life as we know it.

Now Jupiter-sized planets are probably mostly gas and liquid, like Jupiter is, and have no surface for life to evolve on. But such planets may have large solid moons, like Jupiter and Saturn do. On such moons, an atmosphere and oceans may form and remain, so that an environment for life may yet exist in this strange, beautiful system. (We can't find moons yet, only planets, so for now, we have to leave such thoughts to the science fiction writers.)

And those three are only the most interesting of the many discoveries announced at the meeting. We really do seem to be living in a golden age of observational astronomy!

Science Fiction and Astronomy

As regular readers of my blog may know, I have a special interest in science fiction, and often recommend stories in my astronomy and physics classes. I even keep a webpage of science fiction stories that use accurate astronomy, at:http://www.astrosociety.org/scifi

Recently, I joined a writing group, and started writing science fiction myself. After receiving many eloquent rejection notes from some of the finest science fiction magazines, one of my stories was published in a small-press anthology about colonizing Mars, called "Building Red," edited by Janet Cannon.

This coming weekend, I will be a guest speaker at BayCon 2016, a science fiction convention in the San Francisco Bay Area (in San Mateo, to be precise.) I have spoken at such conventions before, but this will be my first time speaking not only as an astronomer, but as a science fiction author. The full program and information is on the website:http://baycon.org.  Please say hello if you stop by.

For those of you not in the area, I discussed my story (and scientists who write science fiction) on the syndicated radio show “Big Picture Science” with host Seth Shostak this week. Here is the page:http://bigpicturescience.org/episodes/science-fiction . Note the things in red are links on this page. If you click on the red “Science Fiction” under download, you will be taken to the audio for the show. The interview that mentions my story starts at about 19 minutes into the show and ends at about 30 minutes into the show.

Seth will also be a speaker at BayCon, as will several NASA scientists. I will even be on a panel on scientific science fiction with two of my favorite science fiction authors, Paul Preuss and G. D. Nordley.

For a person whose life has been mostly about teaching the facts of science, it's a lot of fun to be able to speculate in the realm of fiction. So many of my students tell me they were drawn to astronomy by a science fiction story, TV show, or movie they saw; so I know fiction can help draw new audiences toward astronomy. And with the political news the way it is these days, we all need to find ways to take our minds off our home planet and think about the "bigger picture" of the universe.

Mars: Close and Easy to See (And Wet Long Ago)

Tonight, if you look southeast, you can see Mars as a bright red dot next to the full Moon. Mars is in one of its closer positions, about 48 million miles away. Mars is in what astronomers call "opposition" right now (which is not a term related to the Bernie and Hilary situation!)

When Mars is in opposition, it is on the opposite side of the Earth from the Sun. This means that when the Sun goes down, Mars comes up in our skies, and Mars will be up all night long. (Looking at our diagram from Sky & Telescope magazine, you should also be able to find Saturn this evening or tomorrow night, lower toward the horizon than Mars.)

In recent weeks, even more evidence has been accumulating that ancient Mars, billions of years ago, had a much thicker atmosphere and water was therefore liquid on its surface. Astronomers now believe that there were once lakes and even perhaps seas on the red planet. Recently, planetary scientists even found what seems like evidence of two episodes of tsunamis that happened on Mars a long time ago, when a big chunk of rock or ice from space hit a larger body of water.

For details of this investigation, see: http://www.psi.edu/news/marstsunami

(Also check out a great new Hubble image of Mars at:
http://www.spacetelescope.org/news/heic1609/ )

Special Opportunity to Support the SETI Institute

Some of my regular readers know that for years, I have had the privilege of serving on the Board of Trustees of the SETI Institute, a non-profit organization devoted to the search for life in the solar system and in the universe at large.

As a non-profit organization, the Institute depends on scientific research grants and on donations from members of the public who value its work. This coming week, the Institute is participating in the 2016 Silicon Valley Gives campaign and looking for 500 new donors and friends who want to help underwrite its work -- and be part of the quest to find life elsewhere. We Trustees have provided a $17,000 matching grant – to double any contribution you care to make.

You can be part of the campaign at:https://svgives.razoo.com/us/story/Seti-Institute-2

What kind of projects does the Institute do? You may have heard of the Allen Telescope Array (see the image), a connected group of radio dishes that scans the skies, hoping to eavesdrop on radio signals from an alien civilizations. But Institute’s 80 scientists are also involved with the search for planets orbiting other stars using the Kepler space telescope; with the search for water in the solar system, including on Mars and Jupiter’s moon Europa; with the exploration of Pluto (the Institute’s Mark Showalter discovered two of Pluto’s moons) and other worlds; and much more.

In addition, the Institute’s weekly syndicated show “Big Picture Science” brings humorous, accessible news about scientific ideas and discoveries on radio stations around the country and around the Internet. The Institute has frequent outreach activities in Silicon Valley and beyond. (You can see me explain black holes in six minutes at one of these at:https://www.youtube.com/watch?v=7DX_cc-IjpY )

So won’t you join me in becoming part of the team that works to answer the ancient and beguiling question, “Are we alone in the universe?”

Donations of any size are gratefully accepted at:https://svgives.razoo.com/us/story/Seti-Institute-2

Supersized Black Hole in an Unlikely Location

Astronomers have announced the discovery of a black hole that has “eaten” as much material as 17 billion Suns. A few such gargantuan black holes have been found elsewhere; what makes this one special is that it was found in a poor neighborhood, astronomically speaking.

Black holes are places where matter is so compressed, that nothing – not even light – can escape the grip of gravity. They frequently start life as the collapsed corpse of a massive star, but, under the right circumstances, they can really grow. If a black hole is frequently presented with “food” – matter it can swallow within its tight boundary – that boundary can grow. In a busy region, where lots of material is available, such as the crowded center of a big galaxy, black holes can grow until they contain millions of stars.

Many good-sized galaxies thus contain a “super-massive black hole” at their centers. Our Milky Way Galaxy has such a monster at its heart, which has swallowed enough matter to make 4 million Suns. But that’s still a long way from the super-sized black hole we just found.

Today we also know that galaxies like ours grow over time by swallowing smaller galaxy neighbors, in a process we call galactic cannibalism. If some parts of the victim galaxy are directed toward the giant black hole at the center of the cannibal, it can get swallowed by the giant black hole and help it to grow. (Some of us are reminded by this process of what’s been happening to banks in the U.S., where the largest banks and financial institutions have been swallowing smaller local banks whenever they can.)

At the centers of galaxies that live in a rich neighborhood – filled with other small galaxies they can be thinking about for lunch – giant black holes can grow to be “super-sized.” But in poor neighborhoods, there aren’t that many galaxies to munch on, and we thought black holes at the center of a galaxy would be limited in whether it could grow supersized.

The new discovery, made by a team headed by Berkeley professor Chung-Pei Ma, found the super-sized black hole in a galaxy known by its catalog number, NGC 1600. To our surprise, it resides in a poor neighborhood with only about 20 galaxies hanging out together. How it grew to be one of the largest black holes we know without many victim galaxies around it is still a mystery.

The monstrous black hole is located about 200 million light years from Earth, so that it poses no danger to our own neighborhood and will not interfere with continuing the presidential primaries or other local events. Understanding black holes and their role in the development of galaxies is high on the agenda of astronomers and in NGC 1600 they have a puzzling detail that doesn’t quite fit the standard story line.

For more on how astronomers discover such giant black holes, you can watch the non-technical lecture Chung-Pei Ma gave in the Silicon Valley Astronomy Lectures (that I have the pleasure of moderating) at:https://www.youtube.com/watch?v=LN9oYjNKBm8

(By the way, our image is not real; it is a computer generated field, showing what such a black hole might look like if you could see it close up. We find such black holes by the disturbance or motion they cause in nearby stars.)

The Longest Eclipse Ever Found

This past week there was a beautiful total eclipse of our Sun visible for a few minutes from Indonesia, so it’s a good time to be thinking about all kinds of eclipses. A team of astronomers from several universities recently reported the discovery of a star that is eclipsed for more than 3 years every 69 years. This is the record holder for eclipses anywhere in the universe so far!

What would eclipse a star for such a long period of time? It can’t be a moon, or a planet, or another star, since all of those are too small to cause an eclipse that lasts three and a half years. There must be something around the star that extends over a much larger area and gets in the way of its light as seen from Earth.

After a lot of careful investigation -- using both recent observations by professional and amateur astronomers, and images going back over the last century -- the team concluded that they were seeing two aging stars whirling around each other in 69 years. One of the stars has lost a good deal of its material as it aged, and this lost material now forms a huge disk or doughnut around the emaciated star. It is this large disk that gets in front of the other star and cuts out its light as seen from our viewing angle.

We have seen other systems where such disks cause long eclipses. The best known case is the star Epsilon Aurigae, whose eclipses last about 700 days and happen every 27 years. It too has been studied by large teams of astronomers to uncover its secrets. 

But our star (which has no name, only a long catalog number TYC-2505-672-1) is further away and its eclipses take much longer to repeat. The only way astronomers were able to figure out that it has a 69-year cycle is because they were able to consult a hundred-year repository of pictures of the sky that has been lovingly kept up at the Harvard College Observatory.  

Those old images, many of them made on glass plates back in the days of chemical photography, are a treasure for astronomers. They are now being “digitized” – made into digital images that can be scanned and tracked via computer.

So if astronomers want to know if something interesting (like our eclipse) might have happened to a star sometime in the last century, they can now look up on the Harvard images what that star has been doing all that time. As someone who has trouble throwing out old files or magazines, my heart leapt when I heard about how important the old records were to the discovery!

And how far does stripped star with its disk of dark material have to be from the other star to only have an eclipse every 69 years? Their separation must be more than 20 times the distance between the Earth and the Sun, roughly the distance between the Sun and Uranus.

(The image shows an artist's impression of the dark disk moving in front of a red giant star.)

*****

By the way, to see a nice animation of the dark eclipse spot from the Indonesia eclipse on Earth, go to: https://commons.wikimedia.org/wiki/Category:Solar_eclipse_of_2016_March_9#/media/File:An_EPIC_Eclipse.gif

An "All-American" Eclipse of the Sun Next Year

On August 21, 2017, there will be a gorgeous total eclipse of the Sun visible from the U.S. (and only the US!) The path of what is being called the “All American” total eclipse is only about 60 miles wide and goes from a beach in Oregon to a beach in South Carolina, crossing the country diagonally. (None of our country's largest cities will see it, alas.) A less spectacular partial eclipse will be visible to 500 million people in the other parts of the US and North America.

Astronomers expect tremendous media and public interest in the eclipse and it is not too early to start thinking about how and where best to see it. Eclipse enthusiasts are already busy reserving lodging and viewing space in the narrow region where the total phase can be seen.

The non-profit National Science Teachers Association (NSTA) is making available a popular-level introduction to help explain the eclipse and how to view it. The free 8-page booklet, which I helped write, is available at:http://www.nsta.org/…/f…/solarscience/SolarScienceInsert.pdf

Feel free to share this free booklet with anyone who might be interested.

The eclipse information comes from a new book for educators, entitled Solar Science, which I had the pleasure of writing with my long-time colleague and friend Dennis Schatz. It includes 45 hands-on learning experiences (and lots of background information) about the Sun, the Moon, the sky, the calendar, the seasons, and eclipses. You can see the full table of contents and some sample activities at:http://static.nsta.org/files/PB403Xweb.pdf

Shameless shopping hint: The book could be a wonderful gift for a teacher, a museum or nature center educator, a park ranger, or an amateur astronomer interested in public outreach. See:http://www.nsta.org/store/product_detail.aspx…

But quite separate from the book, please enjoy the free booklet, and, if you can, think about getting to the total eclipse path as part of your summer planning for next year. The image below, by French photographer Luc Viatour, gives you just a taste of how spectacular a total eclipse can be:

NASA is also planning activities and a national website for the eclipse, as is the American Astronomical Society, the main professional organization of astronomers.  I'll let people know when such other resources are available.  In the meantime, the free booklet from NSTA has an eclipse map and information about what will be visible when from many parts of the U.S.  At the end, there are links to sites where you can see very detailed maps of the eclipse path and even commentary about typical August weather at each place.

There is a Possible Super Earth in the Outer Solar System

Out there, way beyond the Sun's family, astronomers have discovered thousands of planets orbiting other stars. Among these alien planets, we have discovered a significant number of "Super Earths" -- planets more massive than our Earth but less massive than the smallest giants in our solar system, Uranus and Neptune. Our solar system has no such Super Earths, but many other systems do; they may be quite common.

Now, Michael Brown and Konstantin Batygin at Caltech, propose that we might just have a Super Earth in our solar system, but so far from the Sun, it takes between 10,000 and 20,000 years to make one orbit! (Pluto, for comparison, takes about 250 years.)

Brown and Batygin have been examining the orbits of icy chunks way beyond Pluto, in the region we call the Kuiper Belt. There are several chunks out there, including one Brown discovered in 2003, called Sedna, that move in an oddly aligned way. After testing many computer models to explain their odd orbit, their best model indicates there could be a planet 10 times the mass of our own Earth, whose stronger gravity is affecting the motions of many objects out where it orbits. Just a few of the affected chunks have been discovered so far and the planet itself has NOT be seen.

So this is a somewhat daring hypothesis, which the two astronomers explain in this brief video: https://www.youtube.com/watch?v=6poHQ2h00ZA

Please note that our image is a painting that Caltech commissioned. No one knows what this Planet Nine looks like.

Now here is the human side of the story. Michael Brown led the team that discovered Eris, the dwarf planet that is the same size as Pluto, in 2005. When he discovered it, he told his wife that he had just discovered a tenth planet and she had made a good decision in marrying him. Alas, instead of being acknowledged as the 10th planet, Eris caused astronomers to rethink the status of Pluto, and remove it from being the 9th planet. Brown was gracious about it, but you can imagine how disappointing it all was for him.

So now Brown may have "discovered" (or at least predicted) a real new planet. He is already nicknaming it "Planet Nine" and it's so big, no one will be able to call it a dwarf! If it is confirmed one day, he can go back to his wife and tell her, "Well, maybe I only discovered a dwarf planet before, but now I have discovered a real planet at last." Not a bad thing to discuss over dinner!

You can see a video where Brown discusses his role in the Pluto and Eris story at: https://www.youtube.com/watch?v=7pbj_llmiMg

Brown and Batygin