New mini-moon about to join Earth's orbit believed to be discarded part of rocket

<p>Mini-moons are typically asteroids which temporarily join the Earth's orbit before being flung back into space.</p><p>However, experts have said the characteristics of this object suggest it isn't an asteroid and is instead consistent with something manmade.</p><p>The object, named 2020 SO, has an Earth-like orbit of a little over a year and low velocity which is not typical of an asteroid.</p><p>Objects arriving from the moon have a lower velocity than asteroids, however experts have said it's slower than moon rocks too.</p><p>A <strong><a href="" target="_blank">NASA</a></strong> official has suggested it may be a discarded part of a rocket which launched experimental payload, Surveyor 2, to study the moon in September 1966.</p><p>The trajectory it is following means 2020 SO is likely to be captured by Earth's gravity in October, and will continue to orbit the planet until around May 2021.</p><p>Despite being considered space junk, 2020 SO has been classified as an Apollo asteroid - these are known to cross paths with Earth's orbit.</p><p>Various mini-moons have been detected in the past, however only two of them have ever been confirmed.</p><p>The first being 2006 RH120, which orbited Earth between 2006 and 2007, and the other <strong><a href="" target="_blank">2020 CD3</a></strong>, which arrived in 2018 before departing earlier this year.</p> <p>Reusable rockets have only been invented in recent times, with multi-stage rockets designed to fall apart being used for decades.</p><p>The booster stage of a rocket falls back to Earth for reuse, however the rest of the rocket is discarded in space after completing its job, resulting in space junk.</p><p>Experts have said due to the various factors in space, items can easily get lost.</p><p>2020 SO is expected to have two near encounters with Earth.</p><p>On 1 December it is expected to pass at a distance of 50,000 kilometres, and on 2 February 2021 it will fly by around 220,000 kilometres away.</p><p>Neither instances will be enough to enter Earth's atmosphere, however they may allow a closer study to determine what the object is.</p>