Alien Atoms: Milky Way Stardust Detected in Solar System

The NASA IBEX probe has for the first time collected interstellar atoms from outside the solar system

The ancients have known for some time that we are made of stardust, but now a NASA spacecraft has detected the actual atoms from outside the solar system.

Researchers on January 31 announced that “interstellar material,” known in layperson’s terms as “alien atoms,” was picked up by the Interstellar Boundary Explorer (IBEX), a NASA spacecraft that floats about 200,000 miles above Earth and monitors the edge of the solar system, according to

"This alien interstellar material is really the stuff that stars and planets and people are made of—it's really important to be measuring it," said David McComas, IBEX principal investigator and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute in San Antonio, at a January 31 news conference at NASA Headquarters in Washington, D.C., according to

For the first time IBEX has detected particles of hydrogen, oxygen and neon, McComas and a team of international scientists announced. Before this, helium was the only substance detected, said. The atoms are literally stardust, detritus from long-ago supernovae, the fiery explosions that end some stars’ lives.

Although it’s only natural that some of the matter would have gotten swept along in the interstellar wind, this is the first time it has been scooped up by a NASA probe, the scientific team said. They found something they didn’t expect: There’s more free-floating oxygen within the solar system than outside it, as the Associated Press reported.

“We discovered this big puzzle—that the matter just outside of our solar system doesn’t look like the material inside,” said McComas.

IBEX was launched in 2008 specifically to study the boundary between the solar system and interstellar space. The solar system is actually contained within a bubble called the heliosphere that protects it from interstellar radiation. The place where the heliosphere meets the rest of the universe is called the heliosheath, which forms a sort of force field that most of the interstellar atoms bounce off of, according to NASA. But some nonmagnetized particles make it through, and these are what were finally sampled by IBEX. The video below explains it all in great detail.

"It's exciting to be able to have these first observations of alien matter—stuff that didn't come from our sun or the planets, but came from the outside of our solar system, from other parts of the galaxy," he said. "We think these are really important measurements, because these elements are the fundamental building blocks of stars, planets, and people."