One of the big news items last week was the prediction that an asteroid was on a collision course with Earth. Although it was a small space rock – estimates ranged from 1-5 meters (3-15 feet), scientists were excited because this was the first time an asteroid was discovered with an imminent known impact. Granted, we’d all probably feel a little safer if we knew about this asteroid, named 2008 TC3, days or months ahead of time instead of only 19 hours, but it’s a step in the right direction. Astronomers even predicted correctly the asteroid would come through the atmosphere over Africa. So with this prediction, many were hoping someone with a camera would be watching the skies of Sudan. But the flight path of the object was over a remote area and so far the only ground-based image that has surfaced is the one shown here, taken by a webcam from a beach in Egypt. (The words on the image indicate the objects on the beach — which were illuminated by the fairly distant explosion low on the horizon.
try to find the tiny bright spot in the center of the image — that’s the asteroid.) But we do have satellites constantly monitoring Earth’s atmosphere and a few of them captured images and data about 2008 TC3. However, it’s not known if any parts of the meteoroid hit the ground.
The explosion was recorded directly by the cameras of a European weather satellite called METEOSAT-8. This was taken in infrared, and the temperature scale on the right is in Kelvin.
Data from this satellite helped determine the asteroid entered Earth’s atmosphere at a velocity of 12.8 kilometers per second. “As it entered the Earth’s atmosphere, it compressed the air in front of it. The compression heated the air, which in turn heated the object to create a spectacular fireball, releasing huge amounts of energy as it disintegrated and exploded in the atmosphere, dozens of kilometers above ground,” the Eumetsat website explains. Meteostat also took a visible image:
Also, according JPL’s Near Earth Object Program, an undisclosed U.S. system has monitored the airburst and yielded a precise time (02:45:45 UTC) and explosive energy equivalent (0.9 to 1.0 kT of TNT). The NEO office also said, “Tthe follow-up astrometric observations from professional and sophisticated amateur astronomers alike were rather extraordinary, with 570 observations from 26 observatories being reported between the time of discovery by the Catalina Sky Survey to just before the object entered Earth’s shadow (57 minutes prior to impact).” These observations revealed a tumbling, rotating object. The CAST astronomical observatory created a “movie” of their observations of the asteroid before it entered into Earth’s shadow.
Here’s links to a few other ground based observatories and their pre-impact sightings: from Eric Allen of Observatoire du Cegep de Trois-Rivieres, Champlain, Quabec; from Ernesto Guido et al. of Remanzacco Observatory, Italy; from S.Korotkiy and T.Kryachko of Kazan State University Astrotel observatory, Russia
Also, SpaceWeather.com reported the crew of an airplane saw a flash in the sky which may have been from this object. But beyond that, sadly, there’s not many images available related to this extraordinary event. If any surface, we’ll be sure to post them.