Moon and Antares
Stars are huge â anywhere from about 10 times the diameter of Earth to a hundred thousand times or more. Such a scale is just hard to fathom. One way to envision it is to consider how long it would take you to make one turn around such a giant body.
An extreme example is Antares, the bright orange heart of Scorpius. Itâs to the lower left of the Moon as they climb into good view tonight, after midnight, and about the same distance to the upper right of the Moon tomorrow night.
Antares is a supergiant â one of the biggest stars in the galaxy. Itâs also one of the brightest and heaviest. The exact numbers are a bit uncertain. In part, thatâs because its outer layers are extremely thin â they just kind of taper off into space. And Antares is blobby instead of perfectly round. But a good estimate says itâs almost 600 million miles in diameter â about 75 thousand times wider than Earth.
To get a better picture of that, imagine flying around Antares in a passenger jet at 600 miles per hour. At that speed, you could circle the Moon in about 11 hours, and Earth in about 40. And it would take six months to circumnavigate the Sun.
For Antares, though, youâd need to pack a lot of movies on your mobile device. Thatâs because it would take 350 years to make one full turn around it â a whole bunch of frequent-flier miles for circling around a supergiant star.
Script by Damond Benningfield
Moon and Antares