A newly discovered asteroid gave our planet a close brush yesterday - and in what may be an astronomical first, observers managed to film the space rock passing in and out of Earth's shadow. Image: Virtual Telescope Project
2016 VA, an object roughly the length of a commercial bus, was discovered yesterday by the Mount Lemmon Sky Survey in Arizona, and later by the International Astronomical Union's Minor Planet Center. A few hours after its discovery, at 11:42AM AEDT, it zipped past our planet, coming within 75,000km at closest approach. That's just 20 per cent of the distance between Earth and the Moon.
Many dozens of space rocks pass within arm's length of our planet each year, but yesterday's celestial interloper was rather special. The Virtual Telescope Project, a series of robotic and remotely-controlled telescopes run by astronomer Gianluca Masi of the of the Bellatrix Astronomical Observatory in Italy, managed to capture stunning footage of 2016 VA careening toward us.
In a blog post, Masi explains how the image above was captured:
A 60-seconds exposure, remotely taken with "Elena" (PlaneWave 17″+Paramount ME+SBIG STL-6303E robotic unit) available at Virtual Telescope. The robotic mount tracked the extremely fast (570″/minute) apparent motion of the asteroid, so stars are trailing. The asteroid is perfectly tracked: it is the sharp dot in the center, marked with two white segments. At the imaging time, asteroid 2016 VA was at about 200.000 km from us and approaching.
Getting such a crisp view of a fast-moving asteroid is impressive enough, but that's not all the Virtual Telescope Project managed to do. Its footage of 2016 VA includes what Masi believes to be the very first video of an asteroid crossing into Earth's umbra, or shadow, and becoming fully eclipsed by our planet. This rare transit began just before the wayward space rock's closest approach, at 10:23AM AEDT, and lasted about 11 minutes.
Here's a sped-up version of the action:
Image: Virtual Telescope Project
For anyone wondering what it'd be like to hitch a ride on an asteroid through Earth's shadow, the Virtual Telescope Project has even put together a nifty orbital simulator. Alien passengers aboard 2016 VA would have experienced a brief solar eclipse, as our planet passed between the sun and their cold, rocky vessel.
With the asteroid not slated for another close encounter with Earth this century, it would have been a sight to behold.