In a recent study published in The Astrophysical Journal, an international team of researchers led by the Carnegie Institution for Science have identified three near-Earth asteroids (NEA) orbiting between Earth and Venus and hiding in the Sun’s glare, with one of them being the largest potentially dangerous asteroid to Earth found in almost a decade. This study is profound since NEAs interior to Earth’s orbit are hard to observe since astronomers are competing with the Sun’s glare. It’s because of this glare that astronomers are forced to make their observations during twilight hours.
"Our twilight survey is scouring the area within the orbits of Earth and Venus for asteroids," said Dr. Scott S. Sheppard, an astronomer with the Carnegie Institution for Science, and lead author of the study. "So far we have found two large near-Earth asteroids that are about 1 kilometer across, a size that we call planet killers."
"There are likely only a few NEAs with similar sizes left to find, and these large undiscovered asteroids likely have orbits that keep them interior to the orbits of Earth and Venus most of the time," said Dr. Sheppard. "Only about 25 asteroids with orbits completely within Earth's orbit have been discovered to date because of the difficulty of observing near the glare of the Sun."
Along with identifying potential “planet killers”, astronomers observe NEAs to help better understand their transportation mechanisms throughout the inner solar system, which encompasses everything between the Sun and the asteroid belt.
For the study, the astronomers used the Dark Energy Camera (DECam) that is mounted on the Victor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile.
"Our DECam survey is one of the largest and most sensitive searches ever performed for objects within Earth's orbit and near to Venus's orbit," said Dr. Sheppard. "This is a unique chance to understand what types of objects are lurking in the inner Solar System."
Sources: The Astrophysical Journal
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