Saturday: Did you get a new telescope for Christmas?
Skyandtelescope.com has a good article on how to get started using it. Go to http://goo.gl/2cJwo. Any observing tip to the
night sky should include Jupiter. Jupiter is three fists held upright and at
arm’s length above the east horizon at 8 p.m. tonight. A small telescope should
reveal Jupiter’s cloud belts and its four largest moons. Last year, the Hubble
Space Telescope discovered plumes of water vapor spewing from the surface of
Europa, one of these large moons. Astronomers have long thought that Europa has
a liquid water ocean below its thick icy crust. But this is the first discovery
of water vapor near Europa. For more information about the plumes, go to http://goo.gl/0FaVs8.
Sunday: Saturn is one fist to the upper right of the moon at
7 a.m.
Monday: Venus is about a half a fist above the southwest
horizon at 5 p.m.
Tuesday: Forget about that big bright ball in Times Square.
You can mark the start of the new year with one of the sky’s own big bright
balls. That perennial favorite New Year’s Day marker, Sirius, the brightest
star in the night sky, rises to its highest point in the sky a little after
midnight on January 1. Thus, when Sirius starts to “fall”, the new year has
begun. Look for Sirius about two and a half fists above due south at midnight.
Wednesday: Today is the day we celebrate the anniversary of
something new – a new classification of celestial objects. Giuseppe Piazzi
discovered Ceres [pronounced sear’-ease], the first of what are now called
“asteroids”, on January 1, 1801. Ceres is the largest asteroid in the belt
between Mars and Jupiter. At first, Piazzi thought it was a star that didn’t
show up on his charts. But, he noted its position changed with respect to the
background stars from night to night. This indicated to him that it had to be
orbiting the Sun. The International Astronomical Union promoted Ceres to the
status of “dwarf planet” in August of 2006.
Thursday: Today’s early morning weather forecast: showers.
Meteor showers, that is. The Quadrantid meteor shower peaks late tonight and
early tomorrow morning between midnight and dawn. Meteor showers are named
after the constellation from which the meteors appear to originate. That makes
this shower mysterious because there isn’t any constellation with this name
now. The shower was named after Quadrans Muralis, an obsolete constellation
found in some early 19th century star atlases. These meteors appear to come
from a point in the modern constellation Draco the dragon. This point is about
three fists above the northeast horizon at 1 a.m. This year, the waning moon
will be rising just before the peak observation time so the dimmer meteors will
be obscured by moonlight. Meteors are tiny rocks that hit the Earth and burn up
in the atmosphere. Most meteors are associated with the path of a comet. This
shower consists of the debris from an asteroid discovered in 2003. Keeping with
the comet-origin paradigm, astronomers think the asteroid is actually an
“extinct” comet, a comet that lost all of its ice as it passed by the Sun
during its many orbits.
Friday: Has it been tough to wake up this past week? It
should have been because the sunrise has been getting a little later since
summer started. I know. I know. December 21 was the shortest day of the year.
But, because the Earth’s orbit around the Sun is elliptical and not circular,
the Earth does not travel at a constant speed. It moves faster when it is closer
to the Sun and slower when it is farther away. This leads to the latest sunrise
occurring around the first of January and the earliest sunset occurring in
early December, not on the first day of winter, the shortest day of the year.
On the first day of winter, however, the interval between sunrise and sunset is
the shortest. For more information, go to http://goo.gl/SJC5r.
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.