Astronomy Picture Of the Day (APOD)Solstice to Solstice Solargraph Timelapse
The 2019 December Solstice, on the first day of winter in planet Earth's northern hemisphere and summer in the south, is at 4:19 Universal Time December 22. That's December 21 for North America, though. Celebrate with a timelapse animation of the Sun's seasonal progression through the sky.
Late Afternoon on Mars
Shadows grow long near sunset in this wide panoramic view from the Curiosity rover on Mars. Made with Curiosity's navcam, the scene covers about 200 degrees from north through east to south (left to right), stitched together from frames taken by the Mars rover on sol 2616. That's just Earth date December 16.
Apollo 17 s Moonship
Awkward and angular looking, Apollo 17's lunar module Challenger was designed for flight in the near vacuum of space. Digitally enhanced and reprocessed, this picture taken from Apollo 17's command module America shows Challenger's ascent stage in lunar orbit.
A Hotspot Map of Neutron Star J0030s Surface
What do neutron stars look like? Previously these city-sized stars were too small and too far away to resolve. Recently, however, the first maps of the locations and sizes of hotspots on a neutron...
The Horsehead Nebula
Sculpted by stellar winds and radiation, a magnificent interstellar dust cloud by chance has assumed this recognizable shape. Fittingly named the Horsehead Nebula, it is some 1,500 light-years distant, embedded in the vast Orion cloud complex.
The Magnetic Fields of Spiral Galaxy M77
Can magnetic fields help tell us how spiral galaxies form and evolve? To find out, the HAWC+ instrument on NASA's airborne (747) SOFIA observatory observed nearby spiral galaxy M77. HAWC+ maps magnetism by observing polarized infrared light emitted by elongated dust grains rotating in alignment with the local magnetic field.
Mammatus Clouds over Nebraska
When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms.
Interstellar Comet 2I Borisov
From somewhere else in the Milky Way galaxy, Comet 2I/Borisov is just visiting the Solar System. Discovered by Crimean amateur astronomer Gennady Borisov on August 30, 2019, the first known interstellar comet is captured in these two recent Hubble Space Telescope images.
Full Moon Geminids
The dependable annual Geminid meteor shower will be near its peak tonight (December 13/14) and before tomorrow's dawn. As Earth crosses through the dusty trail of active asteroid 3200 Phaethon the meteors will flash through the sky from the shower's radiant in Gemini.
Decorating the Sky
Bright stars, clouds of dust and glowing nebulae decorate this cosmic scene, a skyscape just north of Orion's belt. Close to the plane of our Milky Way galaxy, the wide field view spans about 5.5 degrees. Striking bluish M78, a reflection nebula, is on the right.