Jet planes are really fast. They leave long, skinny clouds across the sky like fat chalk lines. These "clouds" are called contrails. Contrails form from the jet engines' exhaust. The exhaust contains water, which quickly freezes into sparkling ice crystals trailing behind the plane.
Well, scientists were surprised to discover recently that a really fast star can leave a sort of contrail too. Mira (MY-rah) is a star that scientists have studied for 400 years. But NASA's Galaxy Evolution Explorer telescope captured a very surprising image of Mira. It showed for the first time that Mira has a long tail of dust and gas—13 light-years long! That is 20,000 times longer than the average distance from the Sun to Pluto!
A star's life has a beginning, middle, and end, just like ours. Only a star's life is much, much longer. Mira is a red giant star near the end of its life. It is blowing off much of its mass in the form of gas and dust. It has already flung out enough material to construct at least 3,000 Earth-sized planets!
Mira is moving at 291,000 miles per hour! This is much faster than the other stars in our part of the Milky Way galaxy. This speed and the huge amount of material coming off Mira have created its contrail-like tail.
Seeing the "invisible"
Now the light our eyes can see is only a teensy part of all the light that exists. Mira's tail is visible only in ultraviolet light, which our eyes cannot see. But the Galaxy Evolution Explorer can. The Explorer is a space telescope whose job is to survey the universe in ultraviolet light. As you can see from Mira, this special telescope is helping scientists make new discoveries about the universe.