Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 August 2

A Moon Dressed Like Saturn

Image Credit & Copyright: Francisco Sojuel

Explanation: Why does Saturn appear so big? It doesn’t — what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow. The Sun directly illuminates the brightly lit lunar crescent from the bottom, which means that the Sun must be below the horizon and so the image was taken before sunrise. This double take-inducing picture was captured on 2019 December 24, two days before the Moon slid in front of the Sun to create a solar eclipse. In the foreground, lights from small Guatemalan towns are visible behind the huge volcano Pacaya.

News: APOD Receives First Outreach Prize from the International Astronomical Union

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 31

Starburst Galaxy M94 from Hubble

Image Credit: ESA/Hubble & NASA

Explanation: Why does this galaxy have a ring of bright blue stars? Beautiful island universe Messier 94 lies a mere 15 million light-years distant in the northern constellation of the Hunting Dogs (Canes Venatici). A popular target for Earth-based astronomers, the face-on spiral galaxy is about 30,000 light-years across, with spiral arms sweeping through the outskirts of its broad disk. But this Hubble Space Telescope field of view spans about 7,000 light-years across M94‘s central region. The featured close-up highlights the galaxy’s compact, bright nucleus, prominent inner dust lanes, and the remarkable bluish ring of young massive stars. The ring stars are all likely less than 10 million years old, indicating that M94 is a starburst galaxy that is experiencing an epoch of rapid star formation from inspiraling gas. The circular ripple of blue stars is likely a wave propagating outward, having been triggered by the gravity and rotation of a oval matter distributions. Because M94 is relatively nearby, astronomers can better explore details of its starburst ring.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 July 29

SOFIA’s Southern Lights

Image Credit & Copyright: Ian Griffin (Otago Museum)

Explanation: SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP aircraft modified to carry a large reflecting telescope into the stratosphere. The ability of the airborne facility to climb above about 99 percent of Earth’s infrared-blocking atmosphere has allowed researchers to observe from almost anywhere over the planet. On a science mission flying deep into the southern auroral oval, astronomer Ian Griffin, director of New Zealand’s Otago Museum, captured this view from the observatory’s south facing starboard side on July 17. Bright star Canopus shines in the southern night above curtains of aurora australis, or southern lights. The plane was flying far south of New Zealand at the time at roughly 62 degrees southern latitude. Unfortunately, after a landing at Christchurch severe weather damaged SOFIA requiring repairs and the cancellation of the remainder of its final southern hemisphere deployment.