Tuesday, December 11, 2018

Andrew Fraknoi: Exploring the Universe: A New Selfie from Mars

Andrew Fraknoi: Exploring the Universe: A New Selfie from Mars: NASA's InSight lander on Mars has sent back its first "selfie" -- a great mosaic of 11 images, taken by the color camera o...

A New Selfie from Mars



NASA's InSight lander on Mars has sent back its first "selfie" -- a great mosaic of 11 images, taken by the color camera on the "elbow" of its robotic arm. You can clearly see the round solar panels (7 feet wide) which collect power for the lander, and, between them, the instrument deck for measuring weather, marsquakes, and other conditions on Mars. Eventually, the instrument package nicknamed the mole will try to dig a hole 16 feet deep and see how heat flows inside the red planet. It's terrific to see InSight's systems slowly being tried out and working so well.

Click on the picture to see it larger.

Wednesday, November 14, 2018

Andrew Fraknoi: Exploring the Universe: A Possible New Planet Around the Second Closest St...

Andrew Fraknoi: Exploring the Universe: A Possible New Planet Around the Second Closest St...: A Possible New Planet Around the Second Closest Star System to Earth An international team of astronomers is announcing the possible d...
A Possible New Planet Around the Second Closest Star System to Earth


An international team of astronomers is announcing the possible discovery of a planet around the second closest star system to us, Barnard’s Star. A mere 6 light-years away, the star is a faint red dwarf which gives off only four hundredths of a percent of the Sun’s light energy. The planet, which could be as massive as 3 Earths, is orbiting at the same distance as Mercury is from the Sun, but is still colder than Saturn and unlikely to harbor life as we know it.
Since the closest star system to us also has a known planet in it, this discovery (if it is confirmed) would make it even more likely that planets are “more common than dirt” out there. Four planetary systems would then be known among the stars 10 light-years or closer. Some 2900 planetary systems (containing almost 4,000 planets) have now been found in our galactic neighborhood.
The new planet, which takes 233 days to orbit, was detected from the very slight “wiggles” that the planet’s gravity (as it goes around) gives to the motion of its star. The wiggles are so small that it took 20 years of observations, using special equipment on various telescopes around the world, to identify them. While it’s still possible that their combined observations have another explanation, the 63 authors on the paper announcing the planet have dug deeply into their data statistics and claim that the planet idea is the most likely explanation. Not all experts in the field agree that this is a definite detection. Instruments of the future, with better ability to detect tiny star wiggles, will ultimately decide if the planet is real.
Our image shows an artist conception of what the the “cold, hostile desert” surface of the planet around Barnard’s Star, with a temperature of -270 degrees Centigrade, might look like. (You will need to take your parka if you go.)

Thursday, August 9, 2018

Perseid Meteor Shower This Weekend



This Sunday evening and Monday morning, there will be one of the best meteor showers you and your family can watch – the Perseids.    And since the Moon will not be in the sky during this shower, dark skies will make it easier for even casual viewers to spot a good number of “shooting stars.”

The best night is the evening of Aug. 12th and morning of Aug. 13th, 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 dark, 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 long dirt and dust stream that we encounter every August.  

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 superheated 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.

MY 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!

[The photo shows a Perseid meteor over the Very Large Telescope at the European Southern Observatory in Chile.]

Sunday, February 4, 2018

Need Listeners' Astronomy Questions for “Fraknoi’s Universe”


With veteran talk-show host and ABC-radio newscaster Gil Gross, we are starting a new series of podcasts to be called “Fraknoi’s Universe.” (It helps to have an unusual last name!)
The pilot episode (made last summer about the total eclipse of the Sun): https://districtproductive.com/fraknois-universe/ was a success on a number of CBS radio stations, and on the Web. So we are starting to record further episodes, discussing the latest news and discoveries from the worlds of astronomy and space exploration.
As part of the program, we’d like to answer general astronomyquestions from interested members of the public. If you have a question (focused on astronomy and space) that you’d like to ask, please e-mail me at:
foothillastroprof@gmail.com
 Be sure you include your full name and home town, so we can mention it on the air.
Feel free to pass this on to others interested in astronomy.
When the shows are ready, we’ll announce them here and on other social media. 
Thanks very much.

Thursday, January 25, 2018

North America to See An Eclipse of the Blue Moon January 31


On Wednesday morning, January 31, residents of North America (and particularly those on the west coast) will experience a rare triple event:
* The full moon will enter the Earth’s shadow and show a total eclipse (turning the full moon into a dark reddish disk)
* This will be the second full moon in the same month – something we call a blue moon
* And it will be a “supermoon,” where the Moon is full just as it’s closest to our planet Earth (this last thing by itself is not especially rare; in fact it will be third “supermoon” in a row).
Having all three together is unusual. The last time we had a blue moon totally eclipsed in the U.S. was more than 150 years ago.

Here are the times of the eclipse of the Moon on the morning of January 31 in different U.S. time zones:
Eclipse Circumstance                  Pacific Mountain Central Eastern
Partial eclipse begins                 3:48 am 4:48 am 5:48 am 6:48 am
Total eclipse begins                   4:52 am 5:52 am 6:52 am ---
Total eclipse ends                      6:08 am 7:08 am ---         ---
Partial eclipse ends                    7:11 am ---         ---         ---
--- means that Moon has already set (is below the horizon)

You can see that in the eastern half of the U.S., the full Moon sets before the total eclipse or just as the eclipse is getting good, but in the western half of the U.S., some or all of the eclipse will be ready to delight those who can get up early (before the Sun does) that morning.
If you are planning to get up to see the last part of the total eclipse, there is one other factor to keep in mind. The eclipsed Moon is setting in the west as the Sun is rising in the east. That means you have to have a clear sight-line toward the western horizon for the eclipse. If buildings or trees block your view in that direction, you could miss the event. So scout out the location where you plan to be in advance. (Maps and charts can be seen at: http://www.skyandtelescope.com/obser…/january-lunar-eclipse/ )
Note: Only the total eclipse turns the Moon an eerie dark red (because of the bending of red light in the Earth’s atmosphere.) Once the total eclipse is over, the reddish effect that eclipse fans like (and the media call a "blood moon") will be gone.

Our remarkable photo, by Elias Politis, shows a 2011 lunar eclipse sequence over the Acropolis in Greece. Click on the image to see it larger.