Earth's Hidden Travelling Companion
Travelling around the Sun with the Earth, always about 60 degrees ahead, is a small asteroid that has been shadowing our planet for thousands of years.
What was reported
In 2010, astronomers studying data from NASA's WISE space telescope found an asteroid about 300 metres across that shares the Earth's orbit around the Sun. Called 2010 TK7, it moves near a point about 60 degrees ahead of the Earth, where the pull of the Earth and the Sun balance.
It was the first 'Trojan' asteroid of Earth to be discovered, like the many Trojans that travel with Jupiter. A second, 2020 XL5, was found in 2020.
Explanations offered
The asteroid wanders back and forth around its balance point in a complicated pattern but never comes very close to the Earth. Trojans are hard to spot from the ground because they appear near the Sun in the sky. It's not a danger to Earth.
- When
- Discovered in 2010
- Where
- Confirmed from Mauna Kea, Hawaii, USA
- Witnesses
- Astronomers using the WISE space telescope
- Status
- Confirmed
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