Saturday: Tonight is a great night to look for the Big Dipper. Tomorrow will be a great night to look for the Big Dipper. In fact, every night for many centuries will be great nights to look for the Big Dipper. But the Big Dipper’s shape slowly changes over many, many, many, many centuries. (Have I reached my word count yet?) Tens of thousands of years ago, it didn’t look like a dipper and tens of thousands of years from now, it will no longer look like a dipper. For a short video simulation of the changing Big Dipper, go to https://youtu.be/txJH8RlIoXQ. For a look at the current Dipper, face northeast at 8:00 p.m. The lowest star, Alkaid, is two and a half fists held upright and at arm's length above the horizon.
Sunday: March to-do list: 1) Move clocks ahead an hour for
daylight saving time, 2) Start spring cleaning, 3) Discover exoplanets. Hmm.
One of these is not like the other. NASA has set up a program through which you
can learn about exoplanets, observe exoplanets, analyze their data, and submit
it to a repository for astronomers to use for their research. Exoplanets are
any planets outside our solar system. For more information about this project,
go to https://exoplanets.nasa.gov/exoplanet-watch/.
Monday: On these late winter mornings, it is still difficult
to get going. You just want to plop into a chair and sit still. But are you
really sitting still? You’re moving at about 700 miles per hour due to the
rotation of the Earth on its axis and 66,000 miles per hour due to the
revolution of the Earth around the Sun. If that’s not enough, the entire solar
system is orbiting the center of the galaxy at a whopping 480,000 miles per
hour! So, while you may be sitting still with respect to your living room (and all
the overachievers in your house), you are NOT sitting still with respect to the
center of the galaxy. For more information about this concept, go to https://nightsky.jpl.nasa.gov/docs/HowFast.pdf.
Tuesday: Deneb is two and a half degrees above the due north
horizon. You can barely fit your thumb between them.
Wednesday: If you ask an astrobiologist for the three most
likely places to find evidence of life in the Solar System, other than Earth,
they’d probably say Mars, Europa (“Didn’t they sing “The Final Countdown”?”),
and Enceladus. Mars makes sense because you know scientists have sent a lot of
probes there. Enceladus, one of Saturn’s moons, is an up-and-coming interest
that first piqued astrobiologists’ interest a few years ago when NASA’s Cassini
probe discovered jets of water containing organic materials shooting out.
Between the pop culture alien hot spot of Mars and the new favorite is
Jupiter’s moon Europa. Astronomers first discovered strong evidence of a large
water ocean on Europa in 1989 during a Galileo flyby. In the next five years,
NASA and the European Space Agency (ESA) will be sending spacecraft to Europa.
For a preview of the ESA JUICE mission and the NASA Europa Clipper mission, go
to https://youtu.be/dAW2uPPS2A4.
Only Jupiter is visible in the evening sky for the next few months. It is three
and a half fists above the west-southwestern horizon at 7:00 p.m.
Thursday: From left to right, Venus, Mars, and the moon are
low on the east-southeastern horizon at 6:00 am
Friday: The bright star Arcturus is nearly three fists above
due east at 10:30 p.m.
The positional information in this column about stars and
planets is typically accurate for the entire week. For up-to-date information
about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.
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