![]() However, only once has a high-speed space rock crashing into the ground been observed both visually and with modern seismic equipment. Scientists have detected the vibrations from meteoroid airbursts using seismic detectors numerous times, including a recent survey of bright meteors above Australia. ![]() Compared to a human lifetime, these events are very rare on Earth. Occasionally, a space rock survives its fiery path through the air and drops to the ground, where it is known as a meteorite.Ī few of these meteorites hit the surface at such speed they blast a hole in the ground called an impact crater. Sometimes a meteoroid explodes when it reaches the thicker atmosphere closer to the ground, creating a spectacular airburst. On Earth, we know these incoming meteoroids as shooting stars, or meteors: beautiful events to observe in the night sky. When a meteoroid encounters a planet with an atmosphere, it heats up due to friction-and may burn up entirely before reaching the ground. The solar system is full of relatively small rocks called meteoroids, and it's common for them to collide with planets. In new research published in Nature Geoscience, we used data from InSight to detect and locate four high-speed meteoroid collisions, and then tracked down the resulting craters in satellite images from NASA's Mars Reconnaissance Orbiter. David Gregory awaiting future donation and can be seen in the Teck Suite of Galleries: Earth’s Treasures.But the internal rumblings of our planetary neighbor aren't the only things that InSight's seismometers detect: they also pick up the thuds of space rocks crashing into the Martian soil. This meteorite is currently on loan from Dr. This glass was likely formed during the high pressure impact event that sent the rock hurtling towards the Earth. The interior is much fresher and contains a mixture of minerals, such as pyroxene and plagioclase, and glass. It was found in March of 2008 and has a distinctive brown exterior caused by weathering (rusting) from sitting on the Earth’s surface. The ROM holds 425 g of NWA 5298 including the main mass which measures 8.5 x 7.5 x 3.5 cm. Most rely on elemental and isotopic compositions that I will not go into here. Since this discovery, a number of other lines of evidence have been found to link all of the martian meteorites. The elements in these trapped gases matched those found in the martian atmosphere. Martian meteorites were first shown to originate from Mars by examining gases trapped in the meteorites. You are probably now thinking – well if these types of rocks can form on Earth, how do we know they are from Mars? Good question. NWA 5298 is similar to rocks on Earth that form from volcanic activity, in fact, it is thought to have formed in a thick lava flow. This month we are looking at a shergottite. This is why you may hear martian meteorites referred to as SNC meteorites. Rocks from Mars are broken down into three categories: shergottites, nakhlites and chassignites. This is not because meteorites hit these areas more often, it just happens to be easier to spot a dark rock from space sitting in the middle of a barren desert. Most meteorites are found in hot and cold deserts. Meteorites are named for where they are found on Earth and in this case (and in many others) our meteorite was found in Northwest Africa. This is probably a good time to teach everyone what these letters represent. This month we take a look at a rock from Mars.Ī number of the meteorites you will see in the “meteorite of the month” blog will have names starting with “NWA”. The Earth has luckily been able to collect a number of meteorites from our moon and from the planet Mars. However, these collisions also happen on the planets and moons in our solar system. Most often we think of them as pieces of rock ejected off of asteroids during big collisions in space. ![]() Meteorites can come from a variety of locations.
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