New Year's Eve Comet

If you have access to a telescope or binoculars and you have a clear sky, you may be able to view Comet 45P/Honda-Mrkos-Pajdušáková near the Moon.

See link below.

Comet 45P/Honda-Mrkos-Pajdušáková

Rosetta Mission

Sometime on November 11, 2014 or November, 12, 2014, the European Space Agency will be landing a probe on a comet. The Rosetta Philae probe was launched on March 2, 2004 with the ultimate goal of orbiting and landing on a comet. The comet that the probe is orbiting and will land on is comet 67P/Churyumov–Gerasimenko and will teach us a lot more about the make up of comets.

Here is a link to the ESA website for the Rosetta mission:
Rosetta Mission

Computer Rendering of Rosetta Probe

"Rosetta" by User:IanShazell - Own work

Kuiper Belt

The Kuiper Belt is the region of the Solar System out beyond Neptune where the majority of our short-period comets are found. This is the region where we find the dwarf planets Pluto and Eris. The objects in this region besides being comets and dwarf planets are sometimes referred to as plutinos, KBOs (cubinos or Kuiper Belt Objects), or TNOs (Trans-Neptunian Objects). The belt is generally a torus centered on the Sun populated mostly by icy bodies as the heavier material generally settled in the interior part of the Solar System.

The comets that come from this region are called short-period comets as they have elliptical orbits with large eccentricities and periods of less than 200 years. They are disturbed in their orbits by large passing bodies, like Neptune that can send the object into in the inner solar system.

The Kuiper Belt is named after Gerard Kuiper as he proposed that there must be a disk that has icy remnants from the formation of the Solar System, much like there is a rocky disk in the inner Solar System containing leftovers from the birth of the Sun and planets, the Asteroid Belt. Disks found around other stars indicate that Kuiper Belt like features may be a consequence of planetary formation around stars.

The disk itself ranges from 30 AU to 100 AU in radius and contains at least several thousand objects, many of which are over 100 km in diamter.

Comet Shoemaker-Levy 9

Hubble Telescope Image of the Comet Shoemaker-Levy 9 before collision with Jupiter

Image Credit:

H.A. Weaver, T. E. Smith (Space Telescope Science Institute), and NASA

 

In 1993, Comet Shoemaker-Levy 9 was discovered by Eugene and Caroline Shoemaker and David Levy in photographs taken of Jupiter. Sometime before its discovery, it passed within the Roche limit of Jupiter and ripped apart by tidal forces from Jupiter's gravity and broke up into 23 individual pieces.

 

Because of its discovery and by following the trajectories of the pieces, the orbits of the pieces could be calculated accurately. From observations, it was determined that the comet would impact Jupiter in July of 1994. This was the first impact that could be accurately predicted and be observed safely as it occured on another planet. The impact of Comet Shoemaker-Levy 9 was going to televised worldwide as this was before the invention of the internet.

 

Over the course of six days, the 23 different pieces of the comet fell on Jupiter. Unfortunately, the impact sites were on the side of Jupiter away from Earth, but luckily on the side that was rotating towards Earth. We might not have seen the impacts directly, but we could see the aftermath on the surface of Jupiter as well as plumes that could be seen over the horizon, if the pieces were large enough.

 

Galileo images of the impact sites

Dept of Physics and Astronomy, University of Tennessee at Knoxville

 

Image of Jupiter with 21 of the fragments

Image Credit:

NASA

MIRAC2 103 micron (one-millionth of a meter) Image of one of the impact

Image Credit:

MIRAC2/NASA/Harvard

 

Watching a comet fall onto Jupiter told us a lot about impacts in the Earth's distant past. It also helped us learn more about Jupiter's atmosphere, which will be addressed in the next post. Early in our history, Earth was continuously bombarded by asteroids and comets, which helped build our planet. In fact, it is believed that the majority of the water on our surface came from the impact of comets with Earth. However, we are not prone to impacts today because there are less asteroids and comets and because Jupiter captures many with its immense gravity. If there was no Jupiter and no large planets, we would be more likely to be impacted by comets and asteroids. If Comet Shoemaker-Levy 9 had hit us, life today might not exist, or at least the kind of life we live today. We should be thankful for Jupiter to vacuum up the majority of the small bodies wandering our Solar System, protecting our planet from catastrophe.

What's in the Sky this Weekend?

If you get up early enough, in the pre-dawn eastern sky, you will be able to see Venus, Jupiter, and the crescent moon relatively close together in the sky.

Both Venus and Jupiter will be to the left of the Moon, with Venus being the brighter of the two objects.

Areavoices Via Astrobob

Also, there is Comet Jacques, a magnitude 5.66 comet in the constellation Cassiopeia, a W shaped (or M shaped) constellation in the northern sky.  It should be pretty easy to see with a good pair of binoculars.  Just look for the fuzzy object with a bluish-green hue.

Astronomy Picture of the Day