Something knocked a chunk off the lunar surface<\/h3>\n
For a while, starting in the year 2016, it looked as if Earth might have a second, much-smaller moon. But, after preliminary studies of the object\u2019s orbit, astronomers labeled 469219 Kamo\u2019oalewa as a near-Earth asteroid (NEA) and a quasi-satellite to Earth.<\/p>\n
So we know that, like our moon, Kamo\u2019oalewa stays close to Earth over many orbital periods, in this case for centuries to come. Kamo\u2019oalewa appears<\/em> as if it circles the Earth. But it doesn\u2019t, although its orbit around the sun is synchronized with Earth\u2019s orbit. <\/p>\n But the moon does figure into Kamo\u2019oalewa\u2019s story. In 2021, astronomers using spectroscopy revealed that Kamo\u2019oalwea might in fact be a piece of the moon. The asteroid and the moon are apparently made of identical stuff: space-weathered silicates. <\/p>\n Now there\u2019s more.<\/p>\n Last Friday (April 19, 2024), another group of astronomers published data in Nature Astronomy supporting a lunar origin for Kamo\u2019oalwea. They also believe they know the impact crater that formed when Kamo\u2019oalewa was blasted from the moon\u2019s surface. <\/p>\n They think they\u2019ve found the scar left by the impact that sent Kamo\u2019oalewa hurtling into space. The far side crater Giordano Bruno \u2013 named for the 16th century Italian philosopher, poet, cosmological theorist and esotericist \u2013 seems to be the \u201clikely\u201d source, they said.<\/p>\n Support astronomy education and our work by donating today. Our organization couldn\u2019t exist without your help!<\/p>\n In reporting the new evidence, Phys.org described the detective work that led an international team of scientists to the suspect crater:<\/p>\n The team began by creating a computer model to mimic the type of collision that could have resulted in a piece of the moon\u2019s surface the size of Kamo\u2019oalewa being flung into space. In so doing they were able to estimate the likely size of the asteroid that would have struck the moon, and from that, the size of the crater it would have left behind.<\/p>\n<\/blockquote>\n Knowing how large the impactor was, and that the impact had to be fairly recent, the team came up with a short list of possible suspects for craters that might match Kamo\u2019oalwea\u2019s origin. As it turned out, one crater had its fingerprints all over the asteroid. From Phys.org:<\/p>\n They then compared samples of moon material brought back to Earth that had been found near one prime possibility \u2013 the Giordano Bruno crater. They found spectral similarities between the samples and the asteroid Kamo\u2019oalewa \u2013 they also found both had bits of the mineral pyroxene in them as well.<\/p>\n<\/blockquote>\n Bingo. Case closed. Or is it?<\/p>\n While it the mystery of Kamo\u2019oalewa\u2019s origin appears solved, a pair of upcoming space probes will test the team\u2019s hypothesis.<\/p>\n First, launching in 2025, the Chinese Tianwen-2 mission will collect a sample of Kamo\u2019oalewa and return it to Earth. According to the Planetary Society:<\/p>\n The spacecraft will rendezvous with asteroid Kamo\u2019oalewa and carry out remote sensing, assessing the planetary body for potential landing sites. It will then attempt to collect samples from the small body using two different techniques \u2014 touch-and-go and anchor-and-attach \u2014 and return to Earth to deliver the samples for analysis. Altogether, this will take around 2.5 years.<\/p>\n<\/blockquote>\n A second mission \u2013 NASA\u2019s NEO Surveyor space telescope launching in 2027 \u2013 should provide more useful data about the orbit of Kamo\u2019oalwea. The NASA mission, however, isn\u2019t about finding the origin of near-Earth objects (NEO). NEO Surveyor hopes to find potentially hazardous asteroids and comets before they find us.<\/p>\n From the NEO Surveyor website:<\/p>\n After launch, NEO Surveyor will carry out a five-year baseline survey to find at least two-thirds of the near-Earth objects larger than 140 meters (460 feet). These are the objects large enough to cause major regional damage in the event of an Earth impact. By using two heat-sensitive infrared imaging channels, NEO Surveyor can make accurate measurements of NEO sizes and gain valuable information about their composition, shapes, rotational states, and orbits.<\/p>\n<\/blockquote>\n Bottom line: A group of astronomers say their data point to a lunar origin for the near-Earth asteroid Kamo\u2019oalewa.<\/p>\n Source: Asteroid Kamo\u2018oalewa\u2019s journey from the lunar Giordano Bruno crater to Earth 1:1 resonance<\/p>\n Via Phys.org<\/p>\n Read more: Piece of the moon? Asteroid might have lunar origin<\/p>\n <\/div>\n![\"A](\"https:\/\/earthsky.org\/upl\/2024\/04\/asteroid-469219-Kamooalewa-e1713989875665.jpg\")
Rounding up the unusual suspects<\/h3>\n
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![\"Map](\"https:\/\/earthsky.org\/upl\/2024\/04\/moon-far-side-Giodano-Bruno-marked-e1713985875414.png\")
<\/figcaption><\/figure>\nSpace missions will continue investigating asteroid Kamo\u2019oalewa<\/h3>\n
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