Magazine Posts

NASA Astronomy Picture of the Day:

A 26 hour old Moon poses behind the craggy outline of the Italian Dolomites in this twilight mountain and skyscape. The one second long exposure was captured near moonset on March 30. And while only a a sliver of its sunlit surface is visible, most of the Moon's disk can be seen by earthshine as light reflected from a bright planet Earth illuminates the lunar nearside. Also known as the Moon's ashen glow, a description of earthshine in terms of sunlight reflected by Earth's oceans illuminating the Moon's dark surface was written over 500 years ago by Leonardo da Vinci. Of course earthshine is just the most familiar example of planetshine, the faint illumination of the dark portion of a moon by light reflected from its planet.

Photo by Giorgia Hofer

Landscape of Pitigliano, Tuscany.

Virtual-Pano, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

Why does Jupiter have rings? Jupiter's main ring was discovered in 1979 by NASA's passing Voyager 1 spacecraft, but its origin was then a mystery. Data from NASA's Galileo spacecraft that orbited Jupiter from 1995 to 2003, however, confirmed the hypothesis that this ring was created by meteoroid impacts on small nearby moons. As a small meteoroid strikes tiny Metis, for example, it will bore into the moon, vaporize, and explode dirt and dust off into a Jovian orbit. The featured image of Jupiter in infrared light by the James Webb Space Telescope shows not only Jupiter and its clouds, but this ring as well. Jupiter's Great Red Spot (GRS) -- in comparatively light color on the right, Jupiter's large moon Europa -- in the center of diffraction spikes on the left, and Europa's shadow -- next to the GRS -- are also visible. Several features in the image are not yet well understood, including the seemingly separated cloud layer on Jupiter's right limb. Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)

Central Berlin (Berlin-Mitte) seen from Fischerinsel.

ArildV, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

Can the Sun appear to rise twice at the same time? This was just the case a few days ago from Les Escoumins, Quebec, Canada as our Solar System's bright central orb rose just as it was being partially eclipsed by the Moon. The featured video shows this unusual double-sunrise in real time and being reflected by the St. Lawrence River. Soon after the initial two spots of light appear over distant clouds, what appears to be bright horns become visible -- which are really just parts of the Sun not being eclipsed. Soon, the entire eclipsed Sun is visible above the horizon. In all, this broken sunrise took less than two minutes during a partial eclipse that lasted many times longer. Although the Moon circles the Earth once a month (moon-th), it does not always eclipse the Sun because its tilted orbit usually takes it above or below. Gallery: Partial Solar Eclipse of 2025 March

Video by Jason Kurth; Music: House of the Rising Sun (Sebastia McQueen via SoundCloud)

The Pillars of Creation captured by the Hubble Space Telescope. Today marks the 20th anniversary of the first photo taken of this structure.

NASA, ESA, and the Hubble Heritage Team (STScI/AURA), Public domain, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

If you watch long enough, a comet will appear. Before then, you will see our Solar System from inside the orbit of Mercury as recorded by NASA's Parker Solar Probe looping around the Sun. The video captures coronal streamers into the solar wind, a small Coronal Mass Ejection, and planets including, in order of appearance, Mercury, Venus, Saturn, Earth, Mars, and Jupiter. Between the emergence of Earth and Mars, Comet Tempel 1 appears with a distinctive tail. The continuous fleeting streaks are high energy particles from the Sun impacting Parker's sideways looking camera. The featured time-lapse video was taken last year during Encounter 21, Parker's 21st close approach to the Sun. Studying data and images from Parker are delivering a better understanding of the dynamic Sun's effects on Earth's space weather as well as humanity's power grids, spacecraft, and space-faring astronauts. Growing Gallery: Partial Solar Eclipse of 2025 March

"Lantingji Xu" scroll (Shenlong version). Today’s lunar calendar day is the third day of March (Chinese: 三月初三), is the Shangsi Festival, a traditional festival in ancient China. Legend has it that on the Shangsi Festival in 353, Wang Xizhi held an Orchid Pavilion Gathering and wrote the "Lantingji Xu". The original is lost. This Tang Dynasty copy by Feng Chengsu (馮承素) is considered the best of all the extant copies.

Feng Chengsu / Wang Xizhi, Public domain, via Wikimedia Commons. View source.