Solar System’s comet-like tail discovered by NASA

SAN ANTONIO, Texas

This image shows a diagram of the sun, the white dot in the center of the circle which represents the inner heliosphere encompassing the entire solar system. A tail of particles flows to the right of the heliosphere. AP photo

Astronomers have gotten the first-ever peek at our solar system’s tail, called the heliotail, finding that it’s shaped like a four-leaf clover, NASA scientists announced July 10. The discovery was made using NASA’s Interstellar Boundary Explorer (IBEX), a coffee table-sized spacecraft that is studying the edge of the solar system, space.com has reported.

“Many models have suggested the heliotail might look like this or like that, but we have had no observations,” David McComas, IBEX principal investigator at Southwest Research Institute in San Antonio, Tex., said in a statement. “We always drew pictures where the tail of the solar system just trailed off the page, since we couldn’t even speculate about what it really looked like.”

Larger than predictions

The tail drags behind the bullet-shaped heliosphere, or the bubble surrounding our solar system that’s created by the solar wind and solar magnetic field. Our heliotail is “a much larger structure with a much more interesting configuration” than scientists had previously predicted, McComas added during a news conference announcing the finding.

Researchers say the comet-like tail is inflated by the solar wind of particles streaming off the sun, and the four-leaf clover shape is the result of fast solar wind shooting out near the sun’s poles and slower wind flowing from near the sun’s equator. The finding is based on the first three years of IBEX’s measurements of energetic neutral atoms.

The lobes of the clover shape do not line up with the solar system perfectly, the scientists found. A slightly rotated shape hints that the particles in the tail are tugged by the magnetic fields from the local galaxy as they move further away from the sun.