Astronomy Picture Of the Day (APOD)APOD: 2023 February 28 Б Crescent Moon Beyond Greek Temple
Why is a thin crescent moon never seen far from a horizon? Because the only geometry that gives a thin crescent lunar phase occurs when the Moon appears close to the Sun in the sky.
APOD: 2023 February 27 Б Zodiacal Ray with Venus and Jupiter
What's causing that unusual ray of light extending from the horizon? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System appears prominently after sunset or before sunrise and is called zodiacal light.
APOD: 2023 February 26 Б Saturns Iapetus: Moon with a Strange Surface
What would make a moon look like a walnut? A strange ridge that circles Saturn's moon Iapetus's equator, visible near the bottom of the featured image, makes it appear similar to a popular edible nut.
Crescent Moon Occultation
On February 22, a young Moon shared the western sky at sunset with bright planets Venus and Jupiter along the ecliptic plane. The beautiful celestial conjunction was visible around planet Earth. But from some locations Jupiter hid for a while, occulted by the crescent lunar disk.
Jones Emberson 1
Planetary nebula Jones-Emberson 1 is the death shroud of a dying Sun-like star. It lies some 1,600 light-years from Earth toward the sharp-eyed constellation Lynx. About 4 light-years across, the expanding remnant...
APOD: 2023 February 23 Arp 78: Peculiar Galaxy in Aries
Peculiar spiral galaxy Arp 78 is found within the boundaries of the head strong constellation Aries. Some 100 million light-years beyond the stars and nebulae of our Milky Way galaxy, the island universe is an enormous 200,000 light-years across.
APOD: 2023 February 22 Б Our Increasingly Active Sun
Our Sun is becoming a busy place. Only two years ago, the Sun was emerging from a solar minimum so quiet that months would go by without even a single sunspot. In contrast, already...
APOD: 2023 February 21 Б Comet ZTF over Yosemite Falls
They are both falling. The water in Yosemite Falls, California, USA, is falling toward the Earth. Comet ZTF is falling toward the Sun. This double cosmic cascade was captured late last month as fading Comet C/2022 E3 (ZTF) had just passed its closest to planet Earth. The orange star just over the falls is Kochab.
APOD: 2023 February 20 Б NGC 1850: Not Found in the Milky Way
There is nothing like this ball of stars in our Milky Way Galaxy. This is surprising because, at first glance, this featured image by the Hubble Space Telescope suggests that star cluster NGC 1850...
APOD: 2023 February 19 Б Seven Dusty Sisters in Infrared
Is this really the famous Pleiades star cluster? Known for its iconic blue stars, the Pleiades is shown here in infrared light where the surrounding dust outshines the stars. Here three infrared colors have been mapped into visual colors (R=24, G=12, B=4.6 microns).