Astronomers have found a potentially hazardous asteroid and one interior to Venus.
. “And so it’s always, I think, a great thing to observe areas that other people aren’t observing.”
Asteroid hunting is already fairly difficult, even when you are searching at night. Near-Earth asteroids appear as very fuzzy, faint points of light zooming through the sky. Asteroids don’t emit light on their own but reflect light coming from the Sun, so it’s easier to see these little dots at night. But we can only see part of the sky in the darkness. “Daytime covers half the sky and nighttime covers half the sky,” says Sheppard.
Searching at twilight can help reveal some of these mysterious objects, but it does make the process of asteroid hunting even harder. Twilight encompasses a period of time about 10 to 15 minutes just before sunrise and 10 to 15 minutes just after sunset. That doesn’t give astronomers a ton of time to find these fuzzy points of light, and then, if they do spot one, they have to reobserve it in the same short timeframe to confirm its position.
The biggest headache of all is the glare of the Sun. “When you take an image, your background is much brighter, so an object doesn’t stand out as easily when you have a really high noisy background,” says Sheppard. Adding to that difficulty is the fact that the telescopes are pointing almost at the horizon in order to observe the sky normally surrounding the Sun.