In about 5 to 8 billion years, our sun is expected to evolve into a white dwarf—an extremely dense, Earth-sized stellar remnant that has exhausted its fuel and shed its outer layer. But while our sun is a solitary star, research over the past 15 years has demonstrated that binary or multi-star systems are far more common than astronomers once thought. When a dense and compact remnant like a white dwarf is involved in a binary system, it often “snatches away” material from its companion star. This process, called accretion, usually emits X-rays in what is considered a “signature” signal.

As four astronauts whiz toward a flyby of the moon, looking out for them are mission control experts using cutting-edge technology and lessons learned from the Apollo program 50 years ago.

The Artemis 2 astronauts have passed the halfway point between Earth and the moon on Saturday as they sped toward a planned lunar flyby, with NASA releasing initial images of Earth taken from inside the Orion spacecraft.

We’re getting closer and closer to finding a real Earth-like exoplanet. But finding one is only half the battle. To truly know if we’re looking at an Earth analog somewhere else in the galaxy, we have to directly image it too. That’s a job for the Habitable Worlds Observatory (HWO), a planned space-based telescope whose primary job is to do precisely that. But even capturing a picture and a planet and getting spectral readings of its atmospheric chemistry still isn’t enough, according to a new paper available on the arXiv preprint server by Kaz Gary of Ohio State and their co-authors. HWO will need to figure out how much a planet weighs first.