Decades ago, astronomers estimated that “ordinary” matter (basically everything that isn’t dark matter or dark energy) makes up 5% of the universe. There was just one problem—they had no idea where ...

Stars don't form out of nothing, but tracking the gas and dust that do eventually form stars is hard. They float around the galaxy at almost absolute zero, emitting essentially no light, and generally ...

The universe is different. “In the interstellar medium,” says Schilke, “argon-36 is by far the most abundant, and we were just too stupid to realize it.” ...

Harvard astronomer Avi Loeb suggests that if interstellar object 3I/ATLAS isn't a comet, nor an asteroid, it may have been ...

The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. Whilst the ISM refers to the matter (interstellar matter, also ...

NASA's Voyager 1 spacecraft made history in 2012 by entering interstellar space, leaving the planets and the solar wind behind. But observations from the pioneering probe were puzzling with regard ...

The Milky Way's interstellar medium—that is, the dust and gas that threads between our galaxy's billions of stars—is an abundant yet elusive material.

We can probe the ionized interstellar medium through imaging and timing observations of compact radio sources. As the radio waves pass through the interstellar medium, they are distorted and delayed ...

The solar system drifts inside an immense, low-density cavity known as the Local Hot Bubble (LHB). This region, spanning at least 1,000 light-years, radiates X-rays due to its searing million ...

Our peer-reviewed reports present the evidence-based consensus of committees of experts. Published proceedings record the presentations and discussions that take place at hundreds of conferences, ...

This probe would take measurements of the plasma and magnetic fields in the interstellar medium and image the heliosphere from the outside. To prepare, NASA asked for input from more than 1,000 ...

An interstellar probe could measure plasma and magnetic fields in the interstellar medium and scan the heliosphere. Skip to content Introducing the all-new Astronomy.com Forum!