New Hubble Image of Jupiter's Red Spot

Astronomers are eagerly awaiting new information about the Great Red Spot, the largest and most colorful storm in the atmosphere of the giant planet Jupiter. The Juno spacecraft just flew as close as 5600 miles over the Red Spot, and the information is coming slowly back to Earth. This giant storm is currently about 10,000 miles wide -- larger than the entire planet Earth -- although it is smaller than when the Voyager spacecraft flew by in the 1970's. Why it has been shrinking and why it's color is so vivid are mysteries planetary scientists are trying to solve. 

In the meantime please enjoy the attached Hubble Space Telescope image of Jupiter, taken on April 3, when the Earth was closest to Jupiter in its yearly orbit. The Red Spot is vividly clear on this wonderfully detailed image, taken from just a few hundred miles above our planet's surface.  (Click on the image to see it bigger.)

New Views of the Planet Jupiter

The first results are in from the Juno mission exploring the giant planet Jupiter, and there are many surprises.

Look at the beautiful image here (click on it to see it bigger), showing the first detailed views of Jupiter's south pole region. The colors are a bit exaggerated, but the structures are real. You are seeing giant cyclones and anti-cyclones, as large as 600 miles across! That's extreme weather the 11 o'clock news team doesn't even dream about.

I'll remind you that Jupiter is not a solid planet -- most of it is made of gas and liquid. Yet there is enough material inside the giant planet to make 318 Earths. Scientists did not know whether at its very center it might have a small solid core or not. Heat from within rises and various molecules move up and down, producing complex bands, zones, and storms in the upper atmosphere.

Additional Juno discoveries include that Jupiter has a bigger core than expected, but that it has a fuzzy-looking structure, as if it were not sharply defined. The giant magnet inside Jupiter that surrounds it with the most powerful magnetic zone of any planet was also found to be stronger than anticipated.

Furthermore, the northern and southern lights on Jupiter are excited not only by charged particles captured from space (as we have on Earth) but also, unexpectedly, from charged particles coming from inside Jupiter.

As usual, when we get better instruments focused on a world or process in astronomy, we find that some of our old assumptions or ideas will need to be revised. That's what makes astronomy so much fun.

Below is an image showing 14 days of the Juno spacecraft approaching and then moving further away from Jupiter's cloudy atmosphere. (Click on it to make it bigger.)

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.

A Wonderfully Scientific Science Fiction Film

Last night, thanks to the Wonderfest organization in San Francisco, I got a chance to see a science fiction film that was in theaters for so short a time that if you blinked, you probably missed it. It's called "Europa Report" and it is the story of a crewed expedition to Jupiter's intriguing moon Europa. This world, one of the four large moons of Jupiter discovered by Galileo, is an ice-covered ball that may well have a large liquid ocean under its surface.

You can see Europa's cracked surface on the picture I have posted above. (This is actually a montage of images from NASA's Galileo spacecraft, with additional image processing by Professor Ted Stryk to bring out more detail.) One possibility is that the dark cracks we see are places where material from deeper inside the Moon (perhaps even from the liquid ocean) is seeping up toward the surface.

In the movie (see the poster below), future astronauts (from a private space company) go to Europa to search for evidence of life. The complex story is told by interweaving the view from cameras in their suits and in their cabins, with footage they recorded for sending back to Earth and interviews with the mission controllers, who eventually lose contact with the ship. What the surviving astronauts eventually find is far more than the micro-organisms scientists currently hope might exist deep under the ice of Europa.

The film, by Ecuadorian director Sebastian Cordero, is now available on DVD and various internet film services. If you enjoy somewhat complicated but scientifically reasonable space stories, I commend it to your attention. If not, spend a little time Googling other images of Europa and check out one of the strangest worlds with which we have the pleasure of sharing the solar system.

Crisis at the Historic Lick Observatory

Lick Observatory, which went into operation in 1888 and was the first mountain-top observatory, is threatened by the budget axe at the University of California. The University President's Office has said that, by 2017-18, it will have to close the still-active observatory (which played a key role in the discovery of the acceleration of the universe, an observation that won the 2011 Nobel Prize in physics.)

You can read the full story in the alumni magazine for the U. of California: http://alumni.berkeley.edu/california-magazine/just-in/2014-02-19/not-licked-yet-fight-keep-iconic-uc-observatory-open

But those of you in the San Francisco Bay Area next week can hear Prof. Alex Filippenko, the President of the Lick Observatory Council, give a free public talk about the latest situation (and what is being discovered at Lick). The talk is Wednesday evening, Feb. 26th, at 7 pm in the Smithwick Theater at Foothill College in Los Altos.

It's part of the Silicon Valley Astronomy Lecture Series, which I have had the pleasure of organizing and moderating for the last 14 years. For more information about the talk and the speaker, and for directions, see:http://www.foothill.edu/news/newsfmt.php?sr=2&rec_id=3270

From its early discovery of the fifth moon of Jupiter's to the recent findings of planets orbiting other stars, the Lick Observatory has a rich history of astronomical work. Plus, it's a premier educational facility, training young astronomers and welcoming tens of thousands of visitors to its spectacular site.

If you don't live in the area, but would like to know more or would like to help, check out the "Save Lick" website:
http://www.ucolick.org/SaveLick/

(The attached photo, taken by Rick Baldridge of the Peninsula Astronomical Society, shows Lick's oldest building in front of the rising full moon.)

I have a special fondness for the Lick Observatory because its first director helped ound the Astronomical Society of the Pacific, where I was the executive director for 14 years.  Plus it's a Bay Area treasure, and its closing would be a tremendous loss for Bay Area astronomy.

Look Up in the Sky Monday Night

As the Sun sets on Monday evening, Jan. 21, and you face South and look up, you should see a pretty sight. The planet Jupiter will be very close to the Moon, almost cheek to cheek with it. Their "closest approach" in the sky will be around 7 pm Pacific time.

The two just happen to look close on the sky -- in reality, Jupiter is 1,700 times further away. Jupiter is the largest planet in our solar system -- eleven Earths could fit side by side into its diameter.

As an extra treat, you get to see the bright star Aldebaran just below the Moon-Jupiter pair. Aldebaran, the reddish eye of the bull figure that gives its name to the constellation of Taurus, is a cool giant star, about 44 times as wide as the Sun. It is about 67 light years away, meaning the light we see tonight took 67 years to get to Earth. If you could see Aldebaran up close, it would shine over 400 times as bright as the Sun. But with all that distance between it and us, it's just a reddish point in our sky.

As you can see in the diagram, the Moon and Jupiter are already close tonight and will still be close on Tuesday night. But Monday is the best time to look up. Take the kids outside in the evening or make a date to be outside with someone with whom you like to spend time in the dark.

(Thanks to Sky & Telescope magazine for the diagram I am showing.)