Saturday: Arcturus is
three fists held upright and at arm’s length above the western horizon at 9:30
p.m. This star, whose name means bear watcher, is the brightest in the sky’s
northern hemisphere. It follows Ursa Major, the Great Bear, around the North
Star. Arcturus is the closest giant star to Earth. It is one of the few stars
whose diameter can be measured directly rather than being inferred from its
density and mass, which themselves are derived from other parameters.
Sunday: Have you
ever gone to a family reunion, looked around and asked, “How in the world are
we related to each other?” Astronomers look around the Solar System and wonder
if there is life anywhere else that we are related to. The Mars Science
Laboratory landed on Mars in 2012 to investigate whether it ever had conditions
favorable for life. The Venus Express studied the atmosphere of Venus from 2006
to 2014. NASA plans to launch the Europa Clipper in 2023 to look for evidence
of current or past life in the Jovian moon’s ice-covered ocean. And NASA just
approved the Dragonfly mission to fly a drone through the atmosphere of
Saturn’s moon Titan to study clues for the origin of life. To learn more about
the search for life in the Solar System and beyond, go to https://www.astrobio.net/, a NASA-sponsored
popular science magazine. While you won’t see anyone waving back, you can see
Jupiter and Saturn in the evening sky. At 9:00 p.m., Jupiter is nearly two
fists above the south-southwestern horizon and Saturn is two fists above the
southern horizon.
Monday: Deneb is
nearly straight overhead at 11 p.m. When you look at Deneb, you are seeing
light that left Deneb about 1,800 years ago.
Tuesday: Spica, the
brightest star in the night sky, is about a half a fist above the southeastern
horizon at 5:30 a.m.
Wednesday: All
stars rotate. Our Sun takes a little less than an Earth month to make one
rotation. Astronomers have started to study the relationship between mass,
stellar rotation, and planetary formation by aiming NASA’s Kepler space
telescope toward the Pleiades open star cluster. All 1,000 stars in this group
is nearly the same age, 125 million years old. Since all of the stars are the
same age and formed from the same set of materials, astronomers have the ideal
“laboratory” to isolate the role star mass plays on star rotation and
evolution. Read more about the findings at http://goo.gl/osijIY. See the Pleiades
for yourself, one fist above the east-northeastern horizon at 11:30 p.m.
Thursday:
Seventeenth century astronomers documented the appearance of a new star, or
“nova”, in 1670. However as modern astronomers studied the records of the star,
called Nova Vulpeculae 1670, they realized it didn’t have the characteristics
of a typical nova because it didn’t repeatedly brighten and dim. It brightened
twice and disappeared for good. Turning their telescopes to the region, they
discovered the chemical signature to be characteristic of a very rare collision
of two stars. For more information about this discovery, go to http://goo.gl/rJnC2G. Nova Vulpeculae
1670 is right below the binary star system Alberio, the head of Cygnus the
swan. Alberio is seven fists above due south at 10:00 p.m.
Friday: Today’s new
Moon is at perigee, meaning it is at its closest point to the Earth for the
month. When the Moon is closer to the Earth, its gravitational tug is greater
and the tides are higher. So that means the tides will be exceptionally high
today.
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.
No comments:
Post a Comment