April 8, 2023 Mercury is at dichotomy today, which is when we see half of Mercury illuminated by the Sun. Like the Moon, Mercury and Venus exhibit phases. This is due to these planets being closer to the Sun than Earth. Mercury at dichotomy, where half the Earth-facing side is illuminated. Image credit: Starry Night
Astronomy Fact of the Day: April 7, 2023
April 7, 2023 Public Telescope Viewing will be held at the James S. McDonnell Planetarium tonight with the St. Louis Astronomical Society. For more information visit www.slsc.org A lunar corona seen from the James S. McDonnell Planetarium. Image credit: Eric Gustafson
Astronomy Fact of the Day: April 6, 2023
April 6, 2023 April’s full moon occurs tonight at 11:35 pm. This is the 4th of 13 full moons this year. In 2023, August will have two full moons. When a month has two full moons, the second one is called a Blue Moon. The Blue Moon in August this year occurs on August 30/31,… Continue reading
Astronomy Fact of the Day: April 5, 2023
April 5, 2023 Sitting outside for about an hour will reveal that the sky changes as the night progresses. This is caused by Earth’s rotation about its axis. This is the same reason the Sun appears to rise in the east and set in the west. The Sun rising in the east and setting in… Continue reading
Astronomy Fact of the Day: April 4, 2023
April 4, 2023 Mercury is now visible 30 minutes after sunset in the west. The next couple of weeks will be your best chance to spot Mercury during its current evening apparition. Tonight, the planet will be found about 9.4° above the western horizon just after sunset. Mercury and Venus seen in the west 30… Continue reading
Desert Rose
Desert Rose – Collected from Mexico Do you see it? The rose-like formation of this gypsum mineral specimen? This is an example of desert rose, a cluster of gypsum with a unique growth pattern of flattened crystal “petals.” Those petals enclose sand grains as they grow, and fan open in a circular series of flat… Continue reading
Astronomy Fact of the Day: April 3, 2023
April 3, 2023 Looking at the moon with binoculars will reveal numerous impact craters. These were caused by objects impacting the lunar surface. This also happens to the Earth but due to weathering, plate tectonics and ocean coverage, we do not see as many on Earth. The Moon in a gibbous phase, as it will… Continue reading
Astronomy Fact of the Day: April 2, 2023
April 2, 2023 The most distant star observed to date is designated WHL-J24.3324-8.477 but it is more commonly called Earendel. This star was discovered in a Hubble deep field image in 2022 due to gravitational lensing caused by the galaxy cluster WHL0137-08. The distance to Earendel is calculated to be roughly 12.9 billion light years.… Continue reading
Astronomy Fact of the Day: April 1, 2023
April 1, 2023 Tonight you will find Venus in the west 20 minutes after sunset. Due to being closer to the Sun than Earth is, Venus exhibits phases. Looking at Venus through a telescope tonight will reveal a gibbous phased Venus with 77% disk illumination. The western sky as it will appear tonight just after… Continue reading
Night Sky Update: March 29 – April 8, 2023
This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Friday, March 29, 2023. Information updated weekly or as needed. Times given as local St. Louis time which is Central Standard Time (CST). For definitions of terminology used in the night sky update, click the highlighted text. If relying on times… Continue reading