7 papers in the free special edition of Science magazine yesterday with results from the Rosetta mission. The duck-shaped comet 67P/Churyumov-Gerasimenko,is giving up its secrets one by one. And its biggest secret may be BOGOF.
Recall this great mission had a long journey to its target and then even landed on the surface of the asteroid.
These set of initial results present new light on many different topics.
First up, the type of water on the comet is not the same type of water we have on Earth. So while comets may still have brought water to Earth, this comet is not an example of one that could have done so.
Second, the comet is spitting out gas in very strange and complex manned. It is a weird comet, after all – it looks more like two comets stuck together, which leads is nicely onto the next finding – maybe it is 2 comets stuck together.It may well turn out that the two blobs of the comet are different material, so this may have started out as two bodies, coallesed into one. So, Buy One Get One Free
Finally, it density is similar to that in the insoles of your new shoes – that aerogel that gives you a nice smooth walk. This is much lighter than anticipated, so the scientific models will have to adapt.
More to come as the comet gets closer to the Sun over the next 8 months.
The Hubble Space Telescope captured this image of Comet C/2012 S1 (ISON) on April 10, 2013 when the comet was slightly closer than Jupiter’s orbit at a distance of 386 million miles from the sun (394 million miles from Earth). This comet is expected to put on a spectacular display in Earth’s sky – visible from both the Northern and Southern Hemisphere – in late 2013. It might even become a daytime comet!
Even at its current great distance from the Earth and sun, the comet is already active as sunlight warms the surface and causes frozen volatiles to sublimate. A detailed analysis of the dust coma surrounding the solid, icy nucleus reveals a strong jet blasting dust particles off the sunward-facing side of the comet’s nucleus. Preliminary measurements from the Hubble images suggest that the nucleus of ISON is no larger than three or four miles across. This is remarkably small considering the high level of activity observed in the comet so far, said researchers. Astronomers are using these images to measure the activity level of this comet and constrain the size of the nucleus, in order to predict the comet’s activity when it skims 700,000 miles above the Sun’s roiling surface on November 28.
The comet’s dusty coma, or head of the comet, is approximately 3,100 miles across, or 1.2 times the width of Australia. A dust tail extends more than 57,000 miles, far beyond Hubble’s field of view. More careful analysis is currently underway to improve these measurements and to predict the possible outcome of the sungrazing perihelion passage of this comet.
ISON stands for International Scientific Optical Network, a group of observatories in ten countries who have organized to detect, monitor, and track objects in space. ISON is managed by the
Institute of Applied Mathematics, part of the Russian Academy of Sciences.
A 10 tonne asteroid has crashed into Russia early this morning. The large piece of space rock probably shattered 20 miles above the ground, it enough fragments made it all the way down to Earth to cause significant damage. The small crater in the ice above is the result of one of the fragments. At least 950 people were injured as the resulting shockwave blew out windows and shook buildings in the Ural Mountains.
“It was quite extraordinary,” Chelyabinsk resident Polina Zolotarevskaya told BBC News. “We saw a very bright light and then there was a kind of a track, white and yellow in the sky.” “The explosion was so strong that some windows in our building and in the buildings that are across the road and in the city in general, the windows broke.”
Your can see it for yourself here
Asteroids this size strike the Earth several hundred times a year, but are mostly over sea or desolate places and mostly burn up. But this event shows that when the trajectory is right, it can cause a lot of damage. Scientists have played down suggestions that there is any link between the event in the Urals and 2012 DA14, an asteroid expected to race past the Earth on Friday at a distance of just 27,700km (17,200 miles) – the closest ever predicted for an object of that size. The two asteroids approached from different directions, so it appears to be a cosmic coincidence.
A comet blazing toward Earth could outshine the full moon when it passes by at the end of next year – if it survives its close encounter with the sun. Comet ISON’s path is very similar to a comet that passed by Earth in 1680, one which was so bright its tail reportedly could be seen in daylight.
The projected orbit of comet ISON is so similar to the 1680 comet, sketched above, that some scientists are wondering if they are fragments from a common parent body.
The recently discovered object, known as comet ISON, is due to fly within 1.2 million miles (1.9 million km) from the center of the sun on November 28, 2013. As the comet approaches, heat from the sun will vaporize ices in its body, creating what could be a spectacular tail that is visible in Earth’s night sky without telescopes or even binoculars from about October 2013 through January 2014.
If the comet survives, that is.
Comet ISON could break apart as it nears the sun, or it could fail to produce a tail of ice particles visible from Earth. Celestial visitors like Comet ISON hail from the Oort Cloud, a cluster of frozen rocks and ices that circle the sun about 50,000 times farther away than Earth’s orbit. Every so often, one will be gravitationally bumped out from the cloud and begin a long solo orbit around the sun.
On September 21, two amateur astronomers from Russia spotted what appeared to be a comet in images taken by a 16-inch (0.4-meter) telescope that is part of the worldwide International Scientific Optical Network, or ISON, from which the object draws its name. Novichonok and co-discoverer Vitali Nevski followed up the next night with a bigger telescope at the Maidanak Observatory in Uzbekistan. Other astronomers did likewise, confirming the object, located beyond Jupiter’s orbit in the constellation Cancer, was indeed a comet.
Comet ISON…could be the brightest comet seen in many generations – brighter even than the full moon.
Comet Halley – the most famous of all comets – last visited Earth in 1986. I remember lying on my bed and staring out my bedroom window at it. But even if you were not alive then, you can still see its effects. Every year at this time the earth moves through the trail of dust, ice, and rubble that the comet left behind. These strike Earth’s atmosphere most fully around October 20-22. As it strikes our atmosphere and begins to fall to Earth, the cometary debris vaporizes, leaving bright streaks across a dark night sky known to us as meteors or shooting stars. Thus, every year at this time, as Earth passes through debris left behind by Comet Halley, we on Earth see the Orionid meteor shower.
In 2012, this shower peaks on the morning of Sunday, October 21. It should be pretty good this year as the waxing crescent moon should be set by midnight. Go have a look tonight, the comet itself will not be back until 2061.