Smallest Near-Earth Object On Space Fully Studied By Arizona Astronomers

The smallest near-Earth object (NEO) in space was discovered by a team of Arizona astronomers in 2015. The near-Earth object named 2015 TC25 is the first one to be fully studied by astronomers using Earth-based telescopes.

The 2015 TC25 NEO is only six-feet in diameter. It is not only the smallest but also the brightest. The asteroid is observed to reflect 60 percent of the light from the Sun that fell on it. The 2015 TC25 NEO was first discovered by the research team during the NASA-funded University of Arizona Catalina Sky Survey in 2015.

Arizona astronomers along with their colleagues from Lowell Observatory and North Arizona University, was able to fully study the near-Earth object 2015 TC15 when it made a flyby 126,000 kilometers from the Earth. The researchers used four Earth-based telescopes for the paper that was published in Astronomical Journal.

The researchers found out that the 2015 TC25 NEO, an asteroid of irregular shape, has a similar surface to a rare highly reflective meteorite called aubrites. Aubrites are made up of bright minerals mostly silicates that are formed in an oxygen-free basaltic environment at very high temperatures. This is quite unique for 2015 TC25 as only one out of a thousand meteorites that fall on Earth belong to the class of aubrites.

According to Audrey Thirouin from Lowell Observatory, "2015 TC25 is one of the five smallest observed NEOs ever observed to measure rotation rate." The NEO is a fast rotator completing one rotation every 2.23 minutes. It is also discovered that the smallest asteroid fully studied is to lack a dust blanket called a regolith and is itself characterized as a monolithic or solid rock.

The near-Earth object 2015 TC25 is a chip off of parent 22-Nysa. 22-Nysa is an asteroid belt that has a diameter of 44 miles. An asteroid belt the size of 22-Nysa can cover a city as large as Los Angeles.

Near-Earth objects like 2015 TC25 is needed to be studied in order to know more about their much larger parent asteroid. Professor Stephen Tegler, the co-author of the paper, says that it is also important to study the physical properties of these NEOs to prepare for threats these objects pose to the planet.