Thanks to the American Astronomical Society, throughout Global Astronomy Month, we will be featuring a Random Astronomy Fact everyday! Come back daily or tune into our social media channels to find out what is the fact of the day!

April 1

Astronomers celebrate International Year of Light 2015! Light from stars, galaxies & more reveals the universe

April 2

The Moon’s light will fade in brief lunar eclipse on April 4th. Google it for the times & areas of visibility.

April 3

1,000 years ago, 7-volume Book of Optics by Ibn Al-Khalili told of experiments on how light travels & reflects.

April 4

Mars probably had an ocean. Some Jupiter & Saturn moons have subsurface seas now. Earth not the only water world.

April 5

Shine flashlight forward as you run: the light waves move no faster than if emitted when you are standing still.

April 6

Some asteroids had strong magnetic fields for 100 million years & more, X-ray studies of meteorite metals reveal.

April 7

Einstein predicted gravity waves from space a century ago. Experimenters hope to detect them within a few years.

April 8

Laser light bounced off the atmosphere helps big ground-based telescopes to take pictures as sharp as Hubble’s.

April 9

NASA probe passes Pluto 14 July after 9.5-yr trip; will take pics in light that left Sun about 4.5 hours earlier. 

April 10

Long before Star Trek, some astronomers claimed a planet Vulcan lies between Mercury & the Sun. Sorry, not there!


April 11

Newton’s prism broke sunlight into colors. Herschel laid a thermometer beyond red from his prism & found infrared.

April 12

A lake of liquid hydrocarbons on Saturn moon Titan is 650 ft deep in one place, more than Lake Superior’s average.

April 13

Radio astronomers are planning 1st observations of the shadow of the giant black hole at the center of our galaxy.

April 14

Matter ejected from 1901 nova explosion in Perseus is still expanding into space at about 700,000 miles per hour.

April 15

So long MESSENGER, NASA probe orbiting Mercury since 2011, sending pix & measurements. Operations are to end soon.

April 16

Air molecules scatter blue light from the Sun in all directions, making the day sky blue. Red is scattered less.


April 17

Centaurs, orbiting amid the outer planets, may have elongated orbits like comets or circular ones like asteroids.

April 18

Some experts estimate billions of stars in our galaxy have planets in habitable zones, where water may be liquid.

April 19

Mark Twain was born & died in yrs that Halley’s Comet came (1910, 1835). Missed it in 1986? Next chance is 2061.

April 20

1st Moon landers Armstrong & Aldrin overshot the certified-safe landing zone by 1 mile. All’s well that ends well!

April 21

Oldest light is the cosmic background radiation, coming in all directions from the Big Bang 13.8 billion yrs ago.

April 22

Mercury is a very hot planet, but there’s water ice in areas near its poles that are always shadowed from the Sun.

April 23

Celebrate tomorrow's 25th anniversary of Hubble Space Telescope launched Apr 24, 1990 on Space Shuttle Discovery!

April 24

Tomorrow is Astronomy Day! See if a local planetarium, museum or astronomy club is holding a public star party!

April 25

Dark energy & dark matter make up almost all mass-energy in the universe. But we don’t know what either one is.

April 26

One supernova in far-off galaxy appears in 4 places on photos. Gravity-bent light took 4 separate paths to Earth.

April 27

When the Moon was 24,000 yrs old, new study says, it orbited so rapidly that full Moons were just 1.5 days apart.

April 28

In some galaxies, stars near the middle orbit in one direction, but stars on the outside move in the opposite way.

April 29

Astronomers now looking for infrared laser pulses from advanced extraterrestrial civilizations (if there are any).

April 30

An asteroid trailing dust may have spun too fast & disrupted, or impact by another space rock knocked stuff off.