Αστρονομική Εικόνα της Ημέρας από τη NASA

Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA

Messier 101

16/05/2025

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was also one of the original spiral nebulae observed by Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. Assembled from 51 exposures recorded by the Hubble Space Telescope in the 20th and 21st centuries, with additional data from ground based telescopes, this mosaic spans about 40,000 light-years across the central region of M101 in one of the highest definition spiral galaxy portraits ever released from Hubble. The sharp image shows stunning features of the galaxy's face-on disk of stars and dust along with background galaxies, some visible right through M101 itself. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away.

A Plutonian Landscape

15/05/2025

This shadowy landscape of majestic mountains and icy plains stretches toward the horizon on a small, distant world. It was captured from a range of about 18,000 kilometers when New Horizons looked back toward Pluto, 15 minutes after the spacecraft's closest approach on July 14, 2015. The dramatic, low-angle, near-twilight scene follows rugged mountains formally known as Norgay Montes from foreground left, and Hillary Montes along the horizon, giving way to smooth Sputnik Planum at right. Layers of Pluto's tenuous atmosphere are also revealed in the backlit view. With a strangely familiar appearance, the frigid terrain likely includes ices of nitrogen and carbon monoxide with water-ice mountains rising up to 3,500 meters (11,000 feet). That's comparable in height to the majestic mountains of planet Earth. The Plutonian landscape is 380 kilometers (230 miles) across.

NGC 1360: The Robin's Egg Nebula

14/05/2025

This pretty nebula lies some 1,500 light-years away, its shape and color in this telescopic view reminiscent of a robin's egg. The cosmic cloud spans about 3 light-years, nestled securely within the boundaries of the southern constellation of the Furnace (Fornax). Recognized as a planetary nebula, egg-shaped NGC 1360 doesn't represent a beginning, though. Instead, it corresponds to a brief and final phase in the evolution of an aging star. In fact, visible at the center of the nebula, the central star of NGC 1360 is known to be a binary star system likely consisting of two evolved white dwarf stars, less massive but much hotter than the Sun. Their intense and otherwise invisible ultraviolet radiation has stripped away electrons from the atoms in their mutually surrounding gaseous shroud. The blue-green hue inside of NGC 1360 seen here is the strong emission produced as electrons recombine with doubly ionized oxygen atoms. Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)

Gaia Reconstructs a Top View of our Galaxy

13/05/2025

What does our Milky Way Galaxy look like from the top? Because we are on the inside, humanity can’t get an actual picture. Recently, however, just such a map has been made using location data for over a billion stars from ESA’s Gaia mission. The resulting featured illustration shows that just like many other spiral galaxies, our Milky Way has distinct spiral arms. Our Sun and most of the bright stars we see at night are in just one arm: Orion. Gaia data bolsters previous indications that our Milky Way has more than two spiral arms. Our Galaxy's center sports a prominent bar. The colors of our Galaxy's thin disk derive mostly from dark dust, bright blue stars, and red emission nebula. Although data analysis is ongoing, Gaia was deactivated in March after a succession mission. Jigsaw Challenge: Astronomy Puzzle of the Day

Gaia Reconstructs a Side View of our Galaxy

12/05/2025

What does our Milky Way Galaxy look like from the side? Because we are on the inside, humanity can’t get an actual picture. Recently, however, just such a map has been made using location data for over a billion stars from ESA’s Gaia mission. The resulting featured illustration shows that just like many other spiral galaxies, our Milky Way has a very thin central disk. Our Sun and all the stars we see at night are in this disk. Although hypothesized before, perhaps more surprising is that the disk appears curved at the outer edges. The colors of our Galaxy's warped central band derive mostly from dark dust, bright blue stars, and red emission nebulas. Although data analysis is ongoing, Gaia was deactivated in March after a successful mission. Explore Your Universe: Random APOD Generator

The Surface of Venus from Venera 14

11/05/2025

If you could stand on Venus -- what would you see? Pictured is the view from Venera 14, a robotic Soviet lander which parachuted and air-braked down through the thick Venusian atmosphere in March of 1982. The desolate landscape it saw included flat rocks, vast empty terrain, and a featureless sky above Phoebe Regio near Venus' equator. On the lower left is the spacecraft's penetrometer used to make scientific measurements, while the light piece on the right is part of an ejected lens-cap. Enduring temperatures near 450 degrees Celsius and pressures 75 times that on Earth, the hardened Venera spacecraft lasted only about an hour. Although data from Venera 14 was beamed across the inner Solar System over 40 years ago, digital processing and merging of Venera's unusual images continues even today. Recent analyses of infrared measurements taken by ESA's orbiting Venus Express spacecraft indicate that active volcanoes may currently exist on Venus. Jigsaw Fun: Astronomy Puzzle of the Day

Yogi and Friends in 3D

10/05/2025

This picture from July 1997 shows a ramp from the Pathfinder lander, the Sojourner robot rover, deflated landing airbags, a couch, Barnacle Bill and Yogi Rock appear together in this 3D stereo view of the surface of Mars. Barnacle Bill is the rock just left of the house cat-sized, solar-paneled Sojourner. Yogi is the big friendly-looking boulder at top right. The "couch" is the angular rock shape visible near center on the horizon. Look at the image with red/blue glasses (or just hold a piece of clear red plastic over your left eye and blue or green over your right) to get the dramatic 3D perspective. The stereo view was recorded by the remarkable Imager for Mars Pathfinder (IMP) camera. The IMP had two optical paths for stereo imaging and ranging and was equipped with an array of color filters for spectral analysis. Operating as the first astronomical observatory on Mars, the IMP also recorded images of the Sun and Deimos, the smallest of Mars' two tiny moons.

IXPE Explores a Black Hole Jet

09/05/2025

How do black holes create X-rays? Answering this long-standing question was significantly advanced recently with data taken by NASA’s IXPE satellite. X-rays cannot exit a black hole, but they can be created in the energetic environment nearby, in particular by a jet of particles moving outward. By observing X-ray light arriving from near the supermassive black hole at the center of galaxy BL Lac, called a blazar, it was discovered that these X-rays lacked significant polarization, which is expected when created more by energetic electrons than protons. In the featured artistic illustration, a powerful jet is depicted emanating from an orange-colored accretion disk circling the black hole. Understanding highly energetic processes across the universe helps humanity to understand similar processes that occur on or near our Earth. Put it All Together: Astronomy Puzzle of the Day

Η Αστρονομική Εικόνα της Ημέρας από τη NASA

The Spiral North Pole of Mars

06/07/2025