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Deborah Byrd

A measurement of all the starlight ever produced

How much starlight has our universe produced? According to a new study, stars have radiated 4×1084 photons since the start of the universe 13.7 billion years ago. That’s the number 4 with 84 zeros behind it.

The Double Cluster in Perseus

The Double Cluster in Perseus consists of 2 star clusters, each containing supergiant suns. Individually, the clusters are known as h and Chi Persei.

See it! Moon and Venus close

The waning crescent moon swept past Venus Monday and Tuesday mornings. The EarthSky community caught photos!

Iridescent cloud with crepuscular rays

You’ll see a true iridescent cloud when the sun is nearby. The colors will appear randomly distributed. Here’s one with beams of light – crepuscular rays, or sunrays – appearing to shoot from it.

Messier 33: 2nd-closest spiral galaxy

The Triangulum galaxy, aka Messier 33, is 2.7 million light-years away, and the 3rd-largest member of our Local Group, after the Milky Way and Andromeda galaxies.

Small asteroid to sweep close this weekend

The low velocity of asteroid 2018 WV1 suggests it’s a fragment of the moon, ejected when a larger asteroid hit the moon long ago. It’ll pass closest during the night Saturday, according to clocks in the Americas.

December guide to the bright planets

In December 2018, the dazzlingly bright object up before the sun is Venus. Mercury and Jupiter join Venus in the east before sunup around mid-December. Saturn sets soon after sunset. Mars stays out until around midnight.

Meet ESA’s SpaceBok robot

The walking and hopping SpaceBok robot is being tested now in ESA’s Mars Yard, in the Netherlands. Someday these little robots might help explore the moon, or Mars.

Last quarter moon is November 29-30

The next last quarter moon falls on November 30, 2018 at 00:19 UTC. A last quarter moon rises around midnight and sets around noon the following day.

InSight lander sets down safely on Mars

There’s a new robot on Mars’ surface, the InSight spacecraft, designed to study the planet’s interior. It set down safely Monday after nearly 7 months of flight from Earth and a 7-minute nail-biting plummet through Mars’ thin atmosphere.