Earth mini-moons may provide testing grounds for space missionsAug 14 (AZINS) Earth's mini-moons - small asteroids temporarily captured in the planet's orbit - could used as test-beds for research and commercial space activities in the future, say scientists. These small and fast-moving visitors have so-far evaded detection by existing technology, with only one confirmed mini-moon discovery to date. The Large Synoptic Survey Telescope (LSST), which is currently under construction will verify their existence and track their paths around our planet, presenting exciting scientific and commercial opportunities, according to study published in the journal Frontiers in Astronomy and Space Science.

"Mini-moons can provide interesting science and technology testbeds in near-Earth space. These asteroids are delivered towards Earth from the main asteroid belt between Mars and Jupiter via gravitational interactions with the Sun and planets in our solar system," said lead author Robert Jedicke, based at the University of Hawaii in the US. "The challenge lies in finding these small objects, despite their close proximity," Jedicke said.

"At present we don't fully understand what asteroids are made of," said Mikael Granvik, affiliated with Lulea University of Technology in Sweden and University of Helsinki in Finland. "Missions typically return only tiny amounts of material to Earth. Meteorites provide an indirect way of analysing asteroids, but Earth's atmosphere destroys weak materials when they pass through," said Granvik. "Mini-moons are perfect targets for bringing back significant chunks of asteroid material, shielded by a spacecraft, which could then be studied in detail back on Earth," he said.

Predicted to be up to 1-2 metres in size, mini-moons are temporarily gravitationally bound in the Earth-Moon system. They may just fly-by the Earth or make at least one revolution around the planet, eventually escaping the gravitational tug of our planet or entering our atmosphere. Reviewing the last ten years of mini-moon research, researchers showed that existing technology can only detect these small, fast moving objects by chance.

"Mini-moons are small, moving across the sky much faster than most asteroid surveys can detect," said Jedicke. "Only one mini-moon has ever been discovered orbiting Earth, the relatively large object designated 2006 RH120, of a few metres in diameter," he said. Expected to become operational in a few years, LSST hopes to confirm the existence of mini-moons and help track their orbits around Earth.

The review highlights the opportunities that the detection of mini-moons will bring, to capitalise on LSST's capabilities once it begins operations. "Once we start finding mini-moons at a greater rate they will be perfect targets for satellite missions," said Jedicke. "We can launch short and therefore cheaper missions, using them as test-beds for larger space missions and providing an opportunity for the fledgling asteroid mining industry to test their technology," he said.