The near-Earth asteroid 2017 GM was discovered by the Mt. Lemmon Survey in Arizona (USA) on April 3, 2017, and, just a few hours later – midday April 4 in Europe, early in the day April 4 for the Americas – it safely came as close as within 10,000 miles of Eath (16,000 km, about 0.04 lunar distances). Our observations helped in determining its orbit.
We captured 2017 GM while it was safely approaching us. For this, we remotely used a telescope in Arizona, made available to the Virtual Telescope by Tenagra Observatories, Ltd. Above is an image coming from a single 30-seconds exposure, unfiltered, taken with the 16?-f/3.75 Tenagra III (“Pearl”) unit. The robotic mount tracked the fast apparent motion (150?/minute) of the asteroid, so stars are trailing. The asteroid is perfectly tracked: it is the sharp dot in the center, marked by two red lines.
On April 4, 2017, at 10:31 UTC (6:31 ET; translate to your time zone), this ~4 meters large rock reached its minimum distance from us of less than 1/20th of the mean lunar distance.
It is among the 10 known asteroids making the closest approach ever.
The observatory is placed at 4,265 feet (1,300 meters) above the sea level, in the Sonoran desert, providing one of the best skies in the world. This image was taken as part of a cooperation between the Virtual Telescope Project and Tenagra Observatories, Ltd., which will be announced soon.
Bottom line: Photo from Virtual Telescope Project and Tenagra Observatories of 2017 GM, an asteroid that is sweeping extremely close to Earth on April 4, 2017.
Gianluca Masi is an Italian astrophysicist and founder of the Virtual Telescope project (part of Bellatrix Astronomical Observatory), consisting in several robotic telescopes, remotely available in real-time over the Internet. Through this system, real-time, online observing sessions are performed, sharing the universe with the world. More than 1 million individuals each year observe the sky through the Virtual Telescope. Gian started his interest in astronomy at childhood, later becoming a professional astronomer, earning a PhD in astronomy in 2006. At the same time, he devoted a lot of efforts to science communication. The asteroid (21795) is named “Masi” in his honor.