At about 10 a.m. Eastern, the space agency will receive its first collected samples from an asteroid, delivered to Earth over the Utah desert.

When asteroid 2020 XL5 was first discovered, astronomer Toni Santana-Ros thought it might have a strange orbit, one that kept it just in front of Earth — what astronomers call a “Trojan asteroid” for the way they sneak behind or in front of a planet.

Well, it’s exactly the approach that I took. I approached this with a scientific mind, like I approach any other problem in astronomy or science that I work on. The point is that we follow the evidence, and the evidence in this particular case is that there are six peculiar facts. And one of these facts is that it deviated from an orbit shaped by gravity while not showing any of the telltale signs of cometary outgassing activity. So we don’t see the gas around it, we don’t see the cometary tail. It has an extreme shape that we have never seen before in either asteroids or comets. We know that we couldn’t detect any heat from it and that it’s much more shiny, by a factor of ten, than a typical asteroid or comet. All of these are facts. I am following the facts.

He noted that the asteroid Bennu — currently under scrutiny by NASA’s Osiris-REx space probe — has a very small chance of hitting Earth a couple of hundred years from now.

n order to obtain an accurate estimate of true completion, and thus population, one must bias-correct the observed re-detection ratio to estimate the true completion as a function of size of asteroid. We do this with a computer model simulating actual surveys.

"Using visible wavelengths of light, it is difficult to tell if an asteroid is big and dark, or bright and small, because both combinations reflect the same amount of light," said Carrie Nugent, a NEOWISE scientist at the Infrared Processing and Analysis Center at California Institute of Technology, in Pasadena. "But when you look at an asteroid in the infrared with NEOWISE, the amount of infrared light corresponds with how big the asteroid is, and with some thermal models on a computer, you can figure out how big the asteroids are."