Both, although the app works better for me than the website. This is 4179 Toutatis/1989 AC, missing by 4,000,000 miles. A Chinese lunar probe will be able to take some close ups when it goes by. Oddly, 2 days ago, an asteroid XE54 missed by 140,000 miles. That one wasn't spotted till two days prior to arrival. Other winners were 2011MD in June 2011, that missed by 7500 miles. And another in 2011 that missed by 3.400 miles. Too small to see until they get close. But also too small to actually hit, they would burn up in the air in a big light show. Except this one tonight, the 4179 Toutatis is 3 miles long. That's big.