Astronomy Picture Of the Day (APOD)APOD: 2023 September 25 Б Arp 142: The Hummingbird Galaxy
What's happening to this spiral galaxy? Just a few hundred million years ago, NGC 2936, the upper of the two large galaxies shown at the bottom, was likely a normal spiral galaxy -- spinning, creating stars -- and minding its own business.
APOD: 2023 September 24 Б A Ring of Fire Sunrise Solar Eclipse
What's rising above the horizon behind those clouds? It's the Sun. Most sunrises don't look like this, though, because most sunrises don't include the Moon. In the early morning of 2013 May 10, however, from Western Australia, the Moon was between the Earth and the rising Sun.
An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day for one year. To make this one, a 4x5 pinhole camera was set up looking north in southern New Zealand skies.
Cosmos in Reflection
During the day, over 12,000 large mirrors reflect sunlight at the 100-megawatt, molten-salt, solar thermal power plant at the western edge of the Gobi desert near Dunhuang, Gansu Province, China. Individual mirror panels turn to track the sun like sunflowers.
The OSIRIS-REx spacecraft's arm reached out and touched asteroid 101955 Bennu on October 20, 2020, after a careful approach to the small, near-Earth asteroid's boulder-strewn surface. Dubbed a Touch-And-Go (TAG) sampling event...
APOD: 2023 September 20 Б Methane Discovered on Distant Exoplanet
Where else might life exist? One of humanity's great outstanding questions, locating planets where extrasolar life might survive took a step forward in 2019 with the discovery of a significant amount of water vapor in the atmosphere of distant exoplanet K2-18b.
APOD: 2023 September 19 Б HH 211: Jets from a Forming Star
Do stars always create jets as they form? No one is sure. As a gas cloud gravitationally contracts, it forms a disk that can spin too fast to continue contracting into a protostar. Theorists hypothesize that this spin can be reduced by expelling jets.
APOD: 2023 September 18 Б The Red Sprite and the Tree
The sprite and tree could hardly be more different. To start, the red sprite is an unusual form of lightning, while the tree is a common plant. The sprite is far away -- high in Earth's atmosphere, while the tree is nearby -- only about a football field away.
APOD: 2023 September 17 Б Moon Mountains Magnified during Ring of Fire Eclipse
What are those dark streaks in this composite image of a solar eclipse? They are reversed shadows of mountains at the edge of the Moon. The center image, captured from Xiamen, China, has the Moon's center directly in front of the Sun's center.
Fireball over Iceland
On September 12, from a location just south of the Arctic Circle, stones of Iceland's modern Arctic Henge point skyward in this startling scene. Entertaining an intrepid group of aurora hunters during a geomagnetic storm, alluring northern lights dance across the darkened sky when a stunning fireball meteor explodes.