Telescopes are capturing meteoroids hitting the Moon and a number of other spacecraft over the years imaged Comet Shoemaker–Levy 9 smacking into Jupiter in 1994. But impacts as they happen on another rocky world haven’t been observed.
However, the MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) mission may see as an impression that happened back in 2013. In watching archival data from the mission, scientists found evidence of a meteoroid impact on Mercury. While this data isn’t a ‘no-doubt’ photo of the event, it does tell scientists more about impacts and the way they affect Mercury’s wispy-thin atmosphere.
Jamie Jasinski said an area physicist that it’s just incredible that MESSENGER could watch this happen. This data plays a very important role in helping us understand how meteoroid impacts contribute material to Mercury’s exosphere.
Mercury’s surface, as captured here in 2013 by the APL operated MESSENGER spacecraft, is pockmarked with craters that have formed from many years of meteoroid impacts. MESSENGER very likely witnessed one among the foremost recent of those crater-forming collisions in 2013.
Mercury’s tiny atmosphere, called an exosphere, features a pressure that’s one-quadrillionth of that felt stumped level on Earth. Mercury’s Sun-facing forms an exosphere side from material originally on the planet’s surface. Scientists think that impacts of meteoroid are liable for putting such material into the exosphere.
The archival data revealed a weird anomaly: on December 21, 2013, MESSENGER’s Fast Imaging Plasma Spectrometer (FIPS) saw a strangely sizable amount of sodium and silicon ions blowing within the Sun’s solar radiation, the powerful charged gases that spew from the Sun. Oddly, these particles were traveling during a tight beam, nearly beat an equivalent direction, and at an equivalent speed.
The researchers rewound the clock that is tracking the particles using the particles speed and direction that motion back to their source. They found the particles clustered during a dense plume, one that had appeared from Mercury’s surface and extended nearly 3,300 miles into space.
They estimate the meteoroid was likely just a touch over three feet long, which is comparatively small. The models created by computers suggest something that size would create a plume with a crest and density closely matching with what FIPS detected. Interestingly enough, before the MESSENGER mission, scientists expected the spacecraft would capture some impacts on Mercury perhaps up to 2 impacts per annum during its four years in orbit. None of them were observed in images during the mission, which lasted from 2011 to 2015.
“It just shows how rare it’s to possess the spacecraft at the proper place and time to be ready to measure something like this,” said study co-author Leonardo Regoli, from Johns Hopkins Applied physics lab in Maryland — where MESSENGER was built and operated. “This was a special observation, and really cool to ascertain the story close.”
Perhaps the European Space Agency’s BepiColombo mission, which launched for Mercury in 2018 and can approach the earth in late 2025, are going to be ready to capture more meteoroid impacts during its mission. Regoli noted that researchers will got to hone their models before using BepiColombo to form new observations, but the chance to ascertain another Mercurian impact would be invaluable, he said.
MESSENGER observed the primary meteoroid impact on another planet’s surface. Neutral atoms emitted by the meteoroid skyrocketed over 3,000 miles above Mercury’s surface, outside the bow shock of Mercury’s magnetosphere. There, photons of sunshine turned the neutral particles into charged particles (ions), which one among MESSENGER’s instruments could detect.