A NASA spacecraft has found the first evidence that our solar system has a tail. NASA's Interstellar Boundary Explorer, or IBEX as it is normally called, mapped the boundaries of the tail for the first time.
It has long been assumed that our solar system sports a tail, much like any object moving through a different medium, like a comet through space, a meteor through the Earth's atmosphere, or even your finger through water.
But NASA scientists were able to map the boundaries of our solar system's heliotail by combining observations from the first three years of IBEX imagery. The tail is a combination of fast and slow moving particles.
Two lines of slower particles appear on the sides, while faster particles can be seen above and below. And the entire structure twists as it goes through the ebb and flow of magnetic fields that exist outside our solar system.
While telescopes have been able to spot tails around other stars, it has been almost impossible to tell whether or not our star has one. The Pioneer 10 probe was headed that direction in 1983 after it crossed Neptune's orbit. However, it lost power in 2003 becore it could reach where the tail was thought to have been.
And the structure can't be seen with a regular telescope, because the particles in the tail don't shine. But IBEX can. The coffee table-sized spacecraft is able to map out regions like the tail by measuring neutral particles that are created by collision that happen at the heliosphere's boundaries. Eric Christian, IBEX mission scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, explained:
"Using neutral atoms, IBEX can observe far away structures, even from Earth orbit. And IBEX scans the entire sky, so it has given us our first data about what the tail of the heliosphere looks like."
The comet-like tail is created and inflated by the solar wind of particles that stream from the sun. It looks like a four-leaf clover because fast solar wind shoots from the sun's poles, while slower-moving wind flows near the sun's equator.
Scientists announced the discovery of our solar system's tail in a news conference. IBEX principal investigator David McComas explained, "Many models have suggested the heliotall might look like this or that, but we have had no observations. He added that our sun's heliotail is "a much larger structure with a much more interesting configuration" than scientists predicted.
What do you think of our solar system's tail?
[Image via NASA/ESA/JPL-Caltech/GSFC/SwRI]