Here's the first image of OSIRIS-REx as it approaches Earth with asteroid sample

This weekend will see the landing of NASA’s first asteroid sample return mission, OSIRIS-REx. The spacecraft visited asteroid Bennu to study, photograph, and scoop up a sample from it, and now OSIRIS-REx is on it’s way back to Earth and is almost here.

On Sunday, September 24, the spacecraft will release the capsule containing the sample, which will land in the Utah desert, where researchers will collect it for study. The spacecraft itself will continue on to study another asteroid, Apophis, and be rechristened OSIRIS-Apex.

This artist’s concept shows NASA’s OSIRIS-REx spacecraft descending towards asteroid Bennu to collect a sample of the asteroid’s surface. — This artist’s concept shows NASA’s OSIRIS-REx spacecraft descending toward asteroid Bennu to collect a sample of the asteroid’s surface. NASA/Goddard/University of Arizona

As the spacecraft approaches, telescopes on the ground have been able to track it, even though the craft is just a few meters across — or about the size of a van. This week, an image was released by the European Space Agency (ESA) from its Optical Ground Station (OGS) telescope in Tenerife, Spain, showing the incoming spacecraft.

Is it a spacecraft? An asteroid? Well, both. This small central speck is the first image of a spacecraft on its way home, carrying with it a sample from an asteroid hundreds-of-millions, if-not-billions-of-years old. The spacecraft is NASA’s OSIRIS-REx, the asteroid is Bennu. — Is it a spacecraft? An asteroid? Well, both. This small central speck is the first image of a spacecraft on its way home, carrying with it a sample from an asteroid that is hundreds of millions of years old. The spacecraft is NASA’s OSIRIS-REx, the asteroid is Bennu. ESA

To create this image, 90 images of around 30-second exposure were combined into one. That allowed the image to show the spacecraft when it was 2.9 million miles away, as captured on September 16. The images couldn’t be simply stacked, however, as the spacecraft is not traveling in a straight line. The images were combined to allow for the spacecraft’s motion, which is why the background stars are blurred.

A visible green laser shone from ESA's Optical Ground Station (OGS). Part of Teide Observatory, the OGS located 2400 m above sea level on the volcanic island of Tenerife, used for the development of optical communication systems for space as well as space debris and near-Earth orbject surveys and quantum communication experiments. The laser looks curved because this picture was taken with a fisheye lens. — A visible green laser shines from The European Space Agency’s Optical Ground Station (OGS). Part of Teide Observatory, the OGS is locate on the volcanic island of Tenerife, Spain, and is used for the development of optical communication systems for space, as well as space debris and near-Earth orbject surveys and quantum communication experiments. The laser looks curved because this picture was taken with a fisheye lens. IAC– Daniel López

The OGS telescope is used to observe targets in the solar system such as space debris and near-Earth asteroids. That’s appropriate as OSIRIS-REx has already visited one near-Earth asteroid, Bennu, which makes regular close approaches to Earth and even has a remote chance of colliding with Earth in the year 2300. However, because of the way that asteroids are tracked, it’s difficult to predict their future trajectories — so researchers typically only consider the possibility of impacts that might occur within the next 100 years. Don’t worry about it, essentially.