Tag: comet

The Largest Object in the Solar System

By Anupum Pant

On November 6th 1892, after being spotted by a British astronomer Edwin Holmes, comet Holmes was not seen again for several decades. Thus it came to be known as the lost comet. Out of the blue, more than 70 years later, the comet was again seen in the year 1964.

Now it is known that comet Holmes was captured by Jupiter several thousand years ago, and it never went back to the Kuiper belt. It is a Jupiter family comet. Every 6.88 years, the comet orbits the sun.

Even this year, on 27th of March, it was one of the most bright comets of the year. But it was something that happened back in the year 2007 which made it one of the most popular comets in the sky.

For a brief period, comet Holmes, which is also a part of our solar system, became the largest object in the solar system. Yes, even larger than the sun!

On November 9th 2007, the diameter of comet’s coma – a cloudy region surrounding the comet made up of very tiny shiny ice and dust particles – measured about 1.4 million km. The sun’s diameter rounded to the nearest hundred is estimated to be 1.392 million km. Agreed the coma wasn’t as massive as the sun, but the size of it did measure slightly more than the sun at that time.

It indeed is a great achievement to become the largest object in the solar system (for some time) for an object that is just a tiny mass of ice and dust that is only about 3.6 km wide.

That day, the cloud around it erupted due to a mysterious outburst which still puzzles scientists. Such outbursts have been seen in the past too and are thought to have been originated as a result of its collision with a meteor (or probably due to an internal steam eruption).

via [space]

Largest Meteorite Left No Crater On Earth

By Anupum Pant

You should know: Meteor vs. Meteoroid vs. Meteorite

Meteor: The streak of light that we see in the sky is “Meteor”. When debris enters earth and gets burned up while entering, it leaves a streak of light. Unlike what is popularly believed, meteor is not the debris itself rather the word “meteor” refers to only the flash of light.

Meteoroid: A meteoroid is a mass that is small – ranging from a kilometer to only a few millimeters in diameter. Most meteoroids that enter the Earth’s atmosphere are so small that they vaporize completely and never reach the planet’s surface.

Meteorite: If the Meteoroid survives and reaches the earth’s surface, it becomes a Meteorite.

Hoba the Meteorite

About 80,000 years back, a ridiculously huge mix of Iron and Nickel entered the earth. It was so large that what was left out of all the burning through the atmosphere, measured 66,000 kg in the end. About half ton of this meteorite has gone to laboratories for research. Even after accounting for losses towards laboratories and vandalism, it is still the largest single mass of natural Iron on the Earth’s surface. It is the largest meteorite ever discovered till date and is called “Hoba”.

This meteorite was discovered by a farmer in Namibia in the year 1920. Since then, due to its mass, it has never been moved. The meteorite and the site has been declared as a national monument by the Namibian government and several tourists visit it every year.

Farmer’s Story: 

One winter as I was hunting at the farm Hoba I noticed a strange rock. I sat down on it. Only its upper part was visible. The rock was black, and all around it was calcareous soil. I scratched the rock with my knife and saw there was a shine beneath the surface. I then chiselled off a piece and took it to the SWA Maatskappy in Grootfontein, whose director established it to be a meteorite.

If that was hardly interesting…

The most puzzling thing about this meteorite is probably not that it belongs to a very rare class of meteorites (Ataxite), but the fact that it has no crater to be seen around it. Normally, a meteorite of this size should have left a crater hundreds of meters wide.

The best theory that explains the absence of any preserved crater around it is that, this piece of rock must have hit the earth’s surface at a very low angle. As a result, it must have skipped on the surface like a flat stone on water surface. And in the end, must have landed at the place where it lies today.