Tech Tuesday: The Blood Moon

Apr 15, 2014

Last night, Mars rose in the east as it passed opposition for 2014, giving lunar observers a rare and ominous treat — the appearance of a "blood moon."

Although the Red Planet gets slightly closer to us over the coming week, opposition marks the point at which Mars is 180 degrees “opposite” to the setting Sun in right ascension as viewed from Earth’s vantage point and denotes the center of the Mars observing season.

The total lunar eclipse of April 2014, as seen from Mt. Lemmon, Arizona.
Credit Mt. Lemmon SkyCenter / University of Arizona

MOSH Planetarium Director Tom Webber sat down with Melissa Ross and gave details about the eclipse and the blood moon, in this week’s Tech Tuesday segment.

“In astronomy, an eclipse simply means one thing is blocking another," Webber said. "In the case of a lunar eclipse, it’s actually the Earth doing the blocking, and so it’s almost better to think that the moon is passing through Earth’s shadow cone, and we might wonder why doesn’t the Moon just disappear?"

"The Earth has this atmosphere that acts like a prism and refracts that red light giving the Moon that blood red color,” Webber said.

Webber said that in astronomy, "opposition" means that celestial bodies are in a straight line.

"I think it’s easy to remember that when we say opposition that means something is on the other side of the Sun," he said. "So when we say Mars opposition we have the Sun, the Earth and then Mars in a straight line when viewed from above.”

Webber said that he is able to incorporate what going on with these planets into an educational setting by using MOSH’s new media globe system.

“It’s the largest digital single lens planetarium in the country and we’re able to simulate the eclipse," he said. "We’re able to talk about Jupiter which is now just west of the meridian after sunset. We’re able to look at the Mars opposition and do computer graphics to show these things."

Opposition only comes around once about every 26 months, so astronomy enthusiasts will likely check out Mars through a telescope during this special time.

You can follow Melissa Ross on Twitter @MelissainJax and Cole Gordon at @Cagordon33Cole.