Is 20 seconds that big of a deal? It is when New Horizons’ observation commands are stored inside its computers and programmed to execute at a certain time.
Issuing these commands via a radio signal from Earth is out of the question. A radio signal from Earth takes four and a half hours to reach Pluto. That’s why the New Horizons team stored the commands on the spacecraft’s computers.
New Horizons detects frozen methane
Astronomers have known about frozen methane on Pluto since first observing it in 1972. But, it is the first time New Horizons has detected it.
NASA also released another timelapse of Pluto and its largest moon, Charon. The video below shows New Horizons approaching the Pluto system from a distance of about 35 million miles to 14 million miles.
Note the contrast between Pluto’s bright northern hemisphere and a dark band of material near its equator.