Astronomy Fact of the Day: September 15, 2018

The Oort Cloud is a source of comets in the solar system which extends 100,000 AU from the sun. Comets from this region are called long-period comets because they can take millions of years to orbit the sun. Learn about the Oort Cloud.

Astronomy Fact of the Day: September 14, 2018

50 years ago the Soviet mission Zond 5 was the first to have earthlings orbit the moon and return safely to Earth. Some of the earthlings aboard were mealworms, tortoises, wine flies and plants. Learn about Zond 5.

Astronomy Fact of the Day: September 13, 2018

At 109 times larger than the Earth, it is hard to imagine our star the Sun is a small star. It is a G-type main sequence star of which range in size from 0.84 to 1.15 solar radii. Fairly small as stars go. Learn about our Sun.

Astronomy Fact of the Day: September 12, 2018

The Earth-Moon orbit, Saturn, OGLE-TR-122b, Jupiter, and other objects, to scale. GPLv2 The smallest and most abundant stars in the galaxy are red dwarfs. These M and K class stars can range in size from 0.08 to 0.50 solar radii. The smallest observed so far is OGLE-TR-122b at 0.12 solar radii. Learn about OGLE-TR-122b.

Astronomy Fact of the Day: September 11, 2018

*Image Credit: Philip Park. CC BY 3.0 The largest star discovered to date is UY Scuti. Located in the summer constellation Scutum, at a distance of roughly 9,500 ly, this red supergiant is roughly 1,700 times larger than our sun. Learn about UY Scuti.

Night Sky Update For The Week of September 11, 2018

This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Tuesday, September 11. All times are given as local St. Louis time (Central Daylight Time). For definitions of terminology used in the night sky update, click the highlighted text. Information updated weekly or as needed. Join us for our next star… Continue reading

Astronomy Fact of the Day: September 10, 2018

*Image provided by ESO/M. Kornmesser. CC BY 4.0 The most massive star discovered to date is R136a1. This is a star that is over 300 times more massive than the sun. It is located 165,000 light years away in the Large Magellanic Cloud. The image shows the relative sizes of young stars, from the smallest… Continue reading

Astronomy Fact of the Day: September 9, 2018

New Moon occurs today starting a new lunar cycle. Our calendar month is based on the lunar phase cycle. The lunar phase cycle lasts about 29.5 days and is called a synodic month. Learn More about lunar phases

Astronomy Fact of the Day: September 8, 2018

Planets are not the only things known to have rings. In 2013 scientists discovered that the 155 mile wide asteroid Chariklo had rings. These rings were discovered as Chariklo occulted a distant star. Learn More about Chariklo