Today: Arcturus is
four fists held upright and at arm’s length above the west-southwest horizon at
8:30 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: This
morning will be the best morning to observe Mercury for the next few weeks.
Mercury is a little less than one fist above the east-northeast horizon at 5:30
a.m. Over the next few weeks, Mercury will move toward the Sun in the sky. By
mid October, it will be visible in the evening sky.
Monday: 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. The Cassini Mission continues to study the plume of complex organic
chemicals streaming from Saturn’s moon Enceladus. NASA and the European Space
Agency are planning missions to study Europa, the Jovian moon with an
ice-covered ocean. And many astronomers consider the methane haze in the
atmosphere in Saturn’s moon Titan similar to that of the early Earth. 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
Venus, Mars, Jupiter, and Saturn in the early night sky. Start with Venus, a
half a fist above the west-southwest horizon at 8:30 p.m. Then move on to
Jupiter, one and a half fists above the southwest horizon.
Tuesday: 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.
Wednesday: Are you
ready for more planets? Saturn is two fists above dus south at 8:40 p.m. At
this time, Mars is one fist above the east-southeast horizon.
Thursday: 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-northeast horizon at 11:30 p.m.
Friday: Yes, I know
the total solar eclipse was one year ago. But one of the best photos was just
released this week. It was, or more accurately, they were taken from a
Southwest Airlines flight from Portland, Oregon to St. Louis, Missouri. Se and
read more about the composite photograph at https://goo.gl/LUQCEP.
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