The asteroid was spotted by the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey at the Mauna Loa Observatory in Hawaii in the early morning hours of Saturday, November 14, just 15 hours after approach. This is not uncommon for fast-movers, especially asteroids that are coming at the Earth from our sunward blind spot, like 2020 VT4.
The asteroid- 2020 VT4 is estimated to be 5 to 10 meters (16-32 feet) across, about the size of a small house. Earth just missed occupying the same space as the perihelion point for the asteroid, which occurred just 20 hours prior to Earth passage.
This sets a record for the closest documented non-meteoric asteroid pass versus the Earth. This record was already broken once this year, with the passage of asteroid 2020 QG 3,000 kilometers (1,864 miles) from the surface of the Earth on August 16. A brilliant bolide was captured on video on the afternoon of August 10, 1972, as it became a brilliant daytime fireball over the Grand Teton Mountains in Wyoming before skipping back out of the Earth's atmosphere. Another recent record was set in October 2008, when astronomers spotted 4-meter (13 foot) asteroid 2008 TC3 19 hours prior to impact, and later recovered fragments in the Nubian Desert in northern Sudan two months later, making 2008 TC3 the first asteroid that was documented before and after impact.