SPACE — Asteroid Bennu has been found to revolve quicker over time, according to research published in Geophysical Research Letters.<br /><br />NASA's OSIRIS-REx began approaching the asteroid last year. The spacecraft travelled 2.2 million kilometers from Earth and stationed itself 19 kilometers from Bennu.<br /><br />The discovery was made via ground-based telescopes and the Hubble Space Telescope. Scientists looked at data from 1999, 2005 and 2013 and observed that the asteroid was increasing its rotational speed over time. <br /><br />According to the study, the OSIRIS-REx spacecraft will independently determine Bennu's speed of rotation by flying closer to the asteroid."<br /><br />The scientists believe that sunlight may be causing Bennu to spin faster as it hits the asteroid from various angles. This is known as the YORP effect.<br /><br />Asteroid Bennu is currently traveling across space at 101,000 kilometers per hour and is able to complete a rotation every 4.3 hours.<br /><br />According to the study, Bennu's speed of rotation has increased by around 1 second per century. The asteroid is estimated to be around 4.5 billion years old.<br /><br />OSIRIS-REx was sent to collect data and sample the asteroid using the Osiris Visible and Infrared Spectrometer and Osiris Thermal Emission Spectrometer.<br /><br />The spacecraft will use its Touch-and-Go Sample Acquisition Mechanism to extract rocks and dirt from the surface of asteroid Bennu in July of 2020.<br /><br />It is expected to travel back to Earth and drop off a capsule containing asteroid samples in September 2023.
