Nasa Image of the Day

Nebula RCW49

One of the most prolific birthing grounds in our Milky Way galaxy, a nebula called RCW 49, is exposed in superb detail for the first time in this new image from NASA's Spitzer Space Telescope. Located 13,700 light-years away in the southern constellation Centaurus, RCW 49 is a dark and dusty stellar nursery that houses more than 2,200 stars.

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New Atlas of the MoonNew Atlas of the Moon has teamed up with to bring you the finest selection of astronomy related books at the best prices.

Browse through our bookstore and check out our fine selection of books from star charts and astrophotography to mathematical astronomy. We are sure you will find the book that best suits your needs.

Sky View Cafe
Sky View Cafe

Sky View Café is a Java applet that lets you use your web browser to see many types of astronomical information, in both graphical and numerical form. You can see which stars and planets will be out tonight in the sky above your home town, see how the next solar or lunar eclipse will look from London, or find out when the Moon rose over Sydney on your birthday ten years ago. Sky View Café includes star charts, a 3-D orrery, displays of the moons of Jupiter and Saturn, an astronomical event calendar, an ephemeris generator, and many other features. Enter Sky View Café now!

Buy A Star Gift - Name a star for any occasion, view it live on Google Sky
Universal Star Registry Certificate Star Naming Service
Name a star for yourself or for that special person as the perfect gift that will sparkle for a lifetime! Ideal for any occassion, birthdays, christenings, anniversaries and memorials. Reserve a place in the heavens for your loved ones

The Sky Tonight Astronomy News
Gravity wonders - Read more >
Mon, 20 May 2019 16:45:00 +0200

Space Science Image of the Week: Black holes provide an extreme cosmic laboratory to test some of the strongest gravity fields in the Universe

Galaxy Blazes with New Stars Born from Close Encounter
Thu, 16 May 2019 10:00:00 EDTHubble Image

One doesn't need a Ph.D. in astrophysics to recognize there is something odd-looking about this otherwise beautiful galaxy, NCG 4485. Like the Batman character Two-Face, one side looks normal, but the other side looks contorted with a firestorm of star formation going on. Why the colorful asymmetry in an island star city many thousands of light-years across? The clue is off the edge of the photo. It's another galaxy, NGC 4490, that swept by NGC 4485 millions of years ago. The gravitational taffy pull between the two galaxies compressed interstellar gas to trigger a flurry of new star birth as seen in the abundance of young blue stars and pinkish nebulas. So, out of a near-collision between two galaxies comes stellar renewal and birth. It's a trademark of our compulsive universe where even things as big as galaxies can go bump in the night.

From canals to craters - Read more >
Thu, 16 May 2019 11:00:00 +0200

Mars was once believed to be criss-crossed by a system of irrigation canals – dark troughs that sliced across the planet’s surface, excavated by an intelligent society of thirsty martians. The astronomer who promoted this idea lends his name to the crater shown in this image from ESA’s Mars Express: Lowell crater.

How Venus and Mars can teach us about Earth - Read more >
Mon, 13 May 2019 18:00:00 +0200

One has a thick poisonous atmosphere, one has hardly any atmosphere at all, and one is just right for life to flourish – but it wasn’t always that way. The atmospheres of our two neighbours Venus and Mars can teach us a lot about the past and future scenarios for our own planet.

ExoMars laboratory passes Red Planet simulation - Read more >
Wed, 08 May 2019 14:00:00 +0200

A key set of scientific instruments developed for the ExoMars rover Rosalind Franklin passed tests last month to ensure compatibility with the martian environment.

The rover’s Analytical Laboratory Drawer (ALD) flight model completed its thermal and vacuum sessions in Turin, Italy, at a Thales Alenia Space facility.

The ExoMars rover will be the first of its kind to both roam the Mars surface and to study it at depth. Rosalind Franklin will drill down to two metres into the surface to sample the soil, analyse its composition and search for evidence of past – and perhaps even present – life hidden underground.

A miniature laboratory inside the rover will analyse the samples and send data and images back to Earth to the scientific community, eager to learn more about our neighbouring planet.

Hubble Astronomers Assemble Wide View of the Evolving Universe
Thu, 02 May 2019 10:00:00 EDTHubble Image

How far is far? And, how do you know when you get there? In 1995, astronomers decided to use the Hubble Space Telescope to conduct a bold and daring experiment to address this puzzle. For 10 consecutive days, Hubble stared at one tiny, seemingly empty patch of sky for 1 million seconds.

The gamble of precious telescope time paid off. Hubble captured the feeble glow of myriad never-before-seen galaxies. Many of the galaxies are so far away it has taken billions of years for their light to reach us. Therefore, the view is like looking down a "time corridor," where galaxies can be seen as they looked billions of years ago. Hubble became astronomy's ultimate time machine.

The resulting landmark image is called the Hubble Deep Field. At the time, the image won the gold medal for being the farthest peek into the universe ever made. Its stunning success encouraged astronomers to pursue a series of Hubble deep-field surveys. The succeeding surveys uncovered more galaxies at greater distance from Earth, thanks to new cameras installed on Hubble during astronaut servicing missions. The cameras increased the telescope's power to look even deeper into the universe.

These surveys provided astronomers with a huge scrapbook of images, showing how, following the big bang, galaxies built themselves up over time to become the large, majestic assemblages seen today in the nearby universe.

Among the most notable deep-field surveys are the Great Observatories Origins Deep Survey (GOODS), in 2003; the Hubble Ultra Deep Field (HUDF), in 2004; and the eXtreme Deep Field (XDF), in 2012.

Now, astronomers are releasing a new deep-field image by weaving together exposures from several of these previous galaxy "fishing expeditions." Their efforts have produced the largest, most comprehensive “history book” of galaxies in the universe. The snapshot, a combination of nearly 7,500 separate Hubble exposures, represents 16 years' worth of observations. The ambitious endeavor is called the Hubble Legacy Field. The new view contains about 30 times as many galaxies as in the HUDF. The wavelength range stretches from ultraviolet to near-infrared light, capturing all the features of galaxy assembly over time.

The image mosaic presents a wide portrait of the distant universe and contains roughly 265,000 galaxies. They stretch back through 13.3 billion years of time to just 500 million years after the universe's birth in the big bang.

Observing Gaia from Earth to improve its star maps - Read more >
Thu, 02 May 2019 15:00:00 +0200

While ESA’s Gaia mission has been surveying more than one billion stars from space, astronomers have been regularly monitoring the satellite’s position in the sky with telescopes across the world, including the European Southern Observatory in Chile, to further refine Gaia’s orbit and ultimately improve the accuracy of its stellar census.

Scientists get to the bottom of a ‘spitting’ black hole - Read more >
Mon, 29 Apr 2019 17:00:00 +0200

Data from ESA’s Integral high-energy observatory have helped shed light on the workings of a mysterious black hole found spitting out ‘bullets’ of plasma while rotating through space. 

Mystery of the Universe's Expansion Rate Widens with New Hubble Data
Thu, 25 Apr 2019 10:00:00 EDTHubble Image

There is something wrong with our universe. Or, more specifically, it is outpacing all expectations for its present rate of expansion.

Something is amiss in astronomers' efforts to measure the past and predict the present, according to a discrepancy between the two main techniques for measuring the universe's expansion rate – a key to understanding its history and physical parameters.

The inconsistency is between the Hubble Space Telescope measurements of today's expansion rate of the universe (by looking at stellar milepost markers) and the expansion rate as measured by the European Space Agency's Planck satellite. Planck observes the conditions of the early universe just 380,000 years after the big bang.

For years, astronomers have been assuming this discrepancy would go away due to some instrumental or observational fluke. Instead, as Hubble astronomers continue to "tighten the bolts" on the accuracy of their measurements, the discordant values remain stubbornly at odds.

The chances of the disagreement being just a fluke have skyrocketed from 1 in 3,000 to 1 in 100,000.

Theorists must find an explanation for the disparity that could rattle ideas about the very underpinnings of the universe.

Hubble Celebrates 29th Anniversary with a Colorful Look at the Southern Crab Nebula
Thu, 18 Apr 2019 10:00:00 EDTHubble Image

This Hubble image shows the results of two stellar companions in a gravitational waltz, several thousand light-years from Earth in the southern constellation Centaurus. The stellar duo, consisting of a red giant and white dwarf, are too close together to see individually in this view. But the consequences of their whirling about each other are two vast shells of gas expanding into space like a runaway hot air balloon. Both stars are embedded in a flat disk of hot material that constricts the outflowing gas so that it only escapes away above and below the stars. This apparently happens in episodes because the nebula has two distinct nested hourglass-shaped structures. The bubbles of gas and dust appear brightest at the edges, giving the illusion of crab legs. The rich colors correspond to glowing hydrogen, sulfur, nitrogen, and oxygen. This image was taken to celebrate Hubble's 29th anniversary since its launch on April 24, 1990.

A “Jellyfish” Galaxy Swims Into View of NASA’s Upcoming Webb Telescope
Wed, 17 Apr 2019 10:00:00 EDTHubble Image

As the spiral galaxy ESO 137-001 plunges into a galaxy cluster, gas is being pulled off of it as though it faced a cosmic headwind. Within that gas, stars are forming to create the appearance of giant, blue tentacle-like streamers. Astronomers, puzzled that stars could form within such tumult, plan to use Webb to study this galaxy and its stellar offspring.

First results from the ExoMars Trace Gas Orbiter - Read more >
Wed, 10 Apr 2019 19:00:00 +0200

New evidence of the impact of the recent planet-encompassing dust storm on water in the atmosphere, and a surprising lack of methane, are among the scientific highlights of the ExoMars Trace Gas Orbiter’s first year in orbit.

ExoMars carrier module prepares for final pre-launch testing - Read more >
Fri, 05 Apr 2019 15:00:00 +0200

The module that will carry the ExoMars rover and surface science platform from Earth to Mars has arrived in Italy for final integration preparations.

BepiColombo is ready for its long cruise - Read more >
Fri, 05 Apr 2019 10:00:00 +0200

Following a series of tests conducted in space over the past five months, the ESA-JAXA BepiColombo mission has successfully completed its near-Earth commissioning phase and is now ready for the operations that will take place during the cruise and, eventually, for its scientific investigations at Mercury.

NASA Awards 2019 Postdoctoral Fellowships
Thu, 04 Apr 2019 10:00:00 EDTHubble Image

NASA has selected 24 new Fellows for its prestigious NASA Hubble Fellowship Program (NHFP). The program enables outstanding postdoctoral scientists to pursue independent research in any area of NASA Astrophysics, using theory, observation, experimentation, or instrument development. Each fellowship provides the awardee up to three years of support.

Mars Express matches methane spike measured by Curiosity - Read more >
Mon, 01 Apr 2019 17:00:00 +0200

A reanalysis of data collected by ESA’s Mars Express during the first 20 months of NASA’s Curiosity mission found one case of correlated methane detection, the first time an in-situ measurement has been independently confirmed from orbit.

Exoplanet satellite ready - Read more >
Fri, 29 Mar 2019 17:00:00 +0100

ESA’s Characterising Exoplanet Satellite, Cheops, was recently declared ready to fly after completing a series of final spacecraft tests.

Hubble Watches Spun-up Asteroid Coming Apart
Thu, 28 Mar 2019 10:00:00 EDTHubble Image

Astronomers once thought asteroids were boring, wayward space rocks that simply orbit around the Sun. These objects were dramatically presented only in science fiction movies.

But recent observations show that asteroids are anything but dull. In reality they are dynamic, active worlds that can ultimately disintegrate due to the long-term subtle effects of sunlight, which can slowly spin them up until they begin to shed material.

Several telescopes, including NASA's Hubble Space Telescope, have caught the gradual self-destruction of the asteroid (6478) Gault. Images from Hubble show two narrow, comet-like tails of dusty debris streaming from the diminutive asteroid.

For Gault, a mass of rubble a few miles across, mere sunlight set the stage for its gradual demise. The force of sunlight, in concert with Gault's own asymmetrical shape, speeded up the asteroid's rotation over a period of more than 100 million years. The estimated spin-up rate is 1 second every 10,000 years.

Today, the asteroid is rotating once every two hours, a speed so fast that it can no longer hold its surface material. The slightest disturbance — perhaps the impact of a pebble, or just a failure of the stressed material — may have set off a collapse. The dust left the asteroid's surface in gentle, short bursts, perhaps due to landslides lasting anywhere from a few hours to a few days. The particles are drifting away from Gault's surface at the speed of a strolling human. The gentle process is like scattering flour into the air, where wind — or sunlight, in the case of Gault — stretches the debris into a long streamer.

Astronomers will monitor the asteroid for future events. About 800,000 known asteroids reside between Mars and Jupiter, and they may fly apart at the rate of roughly one per year.

NASA’s Webb to Explore Galaxies from Cosmic Dawn to Present Day
Thu, 21 Mar 2019 10:00:00 EDTHubble Image

How did the first galaxies in the universe form, and did they make the universe transparent to light? How did later galaxies produce and disperse into the universe the heavier elements that are the building blocks of stars, planets, and even humans? These are questions astronomers will address in some of the first observations made by NASA’s James Webb Space Telescope, slated to launch in March 2021. Astronomers hope the answers will lead to a better understanding of the origins and evolution of the universe.

Mars image bounty - Read more >
Thu, 14 Mar 2019 10:15:00 +0100

Showcase of the ExoMars orbiter’s imaging capabilities

What Does the Milky Way Weigh? Hubble and Gaia Investigate
Thu, 07 Mar 2019 10:00:00 ESTHubble Image

We live in a gigantic star city. Our Milky Way galaxy contains an estimated 200 billion stars. But that's just the bare tip of the iceberg. The Milky Way is surrounded by vast amounts of an unknown material called dark matter that is invisible because it doesn't release any radiation. Astronomers know it exists because, dynamically, the galaxy would fly apart if dark matter didn't keep a gravitational lid on things.

Still, astronomers would like to have a precise measure of the galaxy's mass to better understand how the myriad galaxies throughout the universe form and evolve. Other galaxies can range in mass from around a billion solar masses to 30 trillion solar masses. How does our Milky Way compare?

Curious astronomers teamed up the Hubble Space Telescope and European Space Agency's Gaia satellite to precisely study the motions of globular star clusters that orbit our galaxy like bees around a hive. The faster the clusters move under the entire galaxy's gravitational pull, the more massive it is. The researchers concluded the galaxy weighs 1.5 trillion solar masses, most of it locked up in dark matter. Therefore, the Milky Way is a "Goldilocks" galaxy, not too big and not too small. Just right!

Hubble's Advanced Camera for Surveys Resumes Operations
Wed, 06 Mar 2019 16:15:00 ESTHubble Image

NASA has recovered the Hubble Space Telescope's Advanced Camera for Surveys instrument, which suspended operations on Thursday, Feb. 28, 2019. The final tests were conducted and the instrument was brought back to its operational mode on March 6.

Advanced Camera for Surveys Anomaly on Hubble Space Telescope
Fri, 01 Mar 2019 20:00:00 ESTHubble Image

At 8:31 p.m. EST on February 28, 2019, the Advanced Camera for Surveys (ACS) aboard NASA's Hubble Space Telescope suspended operations after an error was detected as the instrument was performing a routine boot procedure. The error indicated that software inside the camera had not loaded correctly. A team of instrument system engineers, flight software experts, and flight operations personnel quickly organized to download and analyze instrument diagnostic information. This team is currently working to identify the root cause and then to construct a recovery plan.

NASA's Webb Telescope Will Study an Iconic Supernova
Thu, 28 Feb 2019 10:00:00 ESTHubble Image

Within a galaxy known as the Large Magellanic Cloud, a star exploded 160,000 years ago. In 1987, light from that exploding star reached Earth. Over the past 32 years, astronomers have studied Supernova 1987A to learn about the physics of supernovas and their gaseous remnants. Those observations have revealed a surprising amount of dust, up to an entire sun’s worth. NASA’s infrared James Webb Space Telescope will study the dust within SN 1987A to learn about its composition, temperature and density.

Tiny Neptune Moon Spotted by Hubble May Have Broken from Larger Moon
Wed, 20 Feb 2019 13:00:00 ESTHubble Image

The phrase "a chip off the old block" apparently also applies to the outer moons of our solar system.

A tiny moon whirling around Neptune that was uncovered in Hubble Space Telescope photographs taken in 2013 has puzzled astronomers ever since then because it is very close to a much larger moon named Proteus. The orbits of the two moons are presently 7,500 miles apart.

Proteus, at 260 miles in diameter, is roughly the size of the state of Ohio. By contrast, Hippocamp is just 20 miles across, or the size of metropolitan Columbus, Ohio. Proteus should have gravitationally swept aside or swallowed the moon while clearing out its orbital path.

Smoking-gun evidence for Hippocamp's origin comes from NASA Voyager 2 images from 1989 that show a large impact crater on Proteus, almost large enough to have shattered the moon. Apparently, a little piece of Proteus got kicked off and has slowly migrated away from the parent body.

Neptune's satellite system has a violent and tortured history. Many billions of years ago, Neptune captured the large moon Triton from the Kuiper Belt. Triton's gravity would have torn up Neptune's original satellite system. Triton settled into a circular orbit and the debris from shattered Neptunian moons re-coalesced into a second generation of natural satellites. However, comet bombardment continued to tear things up, leading to the birth of Hippocamp, which might be considered a third-generation satellite.

Hubble Reveals Dynamic Atmospheres of Uranus and Neptune
Thu, 07 Feb 2019 10:00:00 ESTHubble Image

The two major planets beyond Saturn have only been visited once by a spacecraft, albeit briefly. NASA's Voyager 2 spacecraft swung by Uranus in 1986, and Neptune in 1989. Our robotic deep-space tourist snapped the only close-up, detailed images of these monstrous worlds. For Neptune, the images revealed a planet with a dynamic atmosphere with two mysterious dark vortices. Uranus, however, appeared featureless. But these views were only brief snapshots. They couldn't capture how the planets' atmospheres change over time, any more than a single snapshot of Earth could tell meteorologists about weather behavior. And, they go through protracted seasonal changes in their multi-decades-long orbits. Ever since the Voyager encounter, the Hubble Space Telescope has provided an opportunity to monitor these worlds like a diligent weatherman.

Since Hubble's launch in 1990, astronomers have used it to amass an album of outer planet images. Yearly monitoring of these giant worlds is now allowing astronomers to study long-term seasonal changes, as well as capture transitory weather patterns. One such elusive event is yet another dark storm on Neptune, shown in the latest Hubble image of the planet (right).

The telescope's new snapshot of Uranus (left) shows that the ice giant is not a planetary wallflower. A vast bright polar cap across the north pole dominates the image. The cap, which may form due to seasonal changes in atmospheric flow, has become much more prominent than in previous observations dating back to the Voyager 2 flyby, when the planet, in the throes of winter, looked bland.

Space science vision - Read more >
Tue, 05 Feb 2019 11:32:00 +0100

How ESA’s space science programme tackles the big questions about our place in the Cosmos

Exoplanet imaginarium - Read more >
Tue, 05 Feb 2019 09:15:00 +0100

Imagine the alien worlds ESA will investigate with its three generations of exoplanet missions

Hubble Accidentally Discovers a New Galaxy in Cosmic Neighborhood
Thu, 31 Jan 2019 10:00:00 ESTHubble Image

The universe is very cluttered. Myriad island cities of stars, the galaxies, form a backdrop tapestry. Much closer to home are nebulae, star clusters, and assorted other foreground celestial objects that are mostly within our Milky Way galaxy. Despite the vastness of space, objects tend to get in front of each other.

This happened when astronomers used the Hubble Space Telescope to photograph the globular star cluster NGC 6752 (located 13,000 light-years away in our Milky Way's halo). In a celestial game of "Where's Waldo?", Hubble's sharp vision uncovered a never-before-seen dwarf galaxy located far behind the cluster's crowded stellar population. The loner galaxy is in our own cosmic backyard, only 30 million light-years away (approximately 2,300 times farther than the foreground cluster).

The object is classified as a dwarf spheroidal galaxy because it measures only around 3,000 light-years at its greatest extent (barely 1/30th the diameter of the Milky Way), and it is roughly a thousand times dimmer than the Milky Way.

Because of its 13-billion-year-old age, and its isolation — which resulted in hardly any interaction with other galaxies — the dwarf is the astronomical equivalent of a living fossil from the early universe.

The international team of astronomers that carried out this study consists of L. Bedin (INAF-Astronomical Observatory of Padua, Italy), M. Salaris (Liverpool John Moores University, Liverpool, England, UK), R. Rich (University of California, Los Angeles, California, USA), H. Richer (University of British Columbia, Vancouver, British Columbia, Canada), J. Anderson (Space Telescope Science Institute, Baltimore, Maryland, USA), B. Bettoni (INAF-Astronomical Observatory of Padua, Italy), D. Nardiello, A. Milone, and A. Marino (University of Padua, Italy), M. Libralato and A. Bellini (Space Telescope Science Institute, Baltimore, Maryland, USA), A. Dieball (University of Bonn, Bonn, Germany), P. Bergeron (University of Montreal, Quebec, Canada), A. Burgasser (University of California, San Diego, California, USA), and D. Apai (University of Arizona, Tucson, Arizona, USA).

The science team's results will be published online January 31, 2019, in the Monthly Notices of the Royal Astronomical Society: Letters.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

World's Largest Digital Sky Survey Issues Biggest Astronomical Data Release Ever
Mon, 28 Jan 2019 09:00:00 ESTHubble Image

Data from the world's largest digital sky survey is being publicly released today by the Space Telescope Science Institute (STScI) in Baltimore, Maryland, in conjunction with the University of Hawai’i Institute for Astronomy in Honolulu, Hawaii. Data from the Pan-STARRS1 Surveys will allow anyone to access millions of images and use the database and catalogs containing precision measurements of billions of stars and galaxies. This data release contains over 1.6 petabytes of data (a petabyte is one million gigabytes), making it the largest volume of astronomical information ever released. The survey data resides in the Mikulski Archive for Space Telescopes (MAST), which serves as NASA's repository for all of its optical and ultraviolet-light observations.

Hubble Sees Plunging Galaxy Losing Its Gas
Thu, 24 Jan 2019 13:00:00 ESTHubble Image

Two's company and three's a crowd. But thousands are a mosh pit. That's the case in the giant Coma cluster of more than 1,000 galaxies.

Hubble spotted a wayward spiral galaxy losing its gas as it plunges toward the center of the massive cluster and is roughed up as it plows through the intergalactic medium. Telltale evidence lies in a long, thin streamer of material that is stretching like taffy from the galaxy's core and on into intergalactic space. Gas is the lifeblood of a galaxy, fueling the birth of new stars. Once it is stripped of all of its gas, the galaxy, named D100, will enter retirement and shine only by the feeble glow of its aging, red stars.

D100 is being stripped of its gas because of the gravitational tug of a grouping of giant "bully" galaxies in the crowded cluster. Their combined gravity is pulling the beleaguered galaxy toward the cluster's center. As D100 falls toward the core, the galaxy barrels through material. This action forces gas from the galaxy.

The gas-stripping process in D100 began roughly 300 million years ago. In the massive Coma cluster this violent gas-loss process occurs in many galaxies. But D100 is unique in several ways. Its long, thin tail is its most unusual feature extending nearly 200,000 light-years. But the pencil-like structure is comparatively narrow, only 7,000 light-years wide. Thankfully, our Milky Way galaxy lives in a sparsely populated small corner of the universe, with only one other big galaxy as a companion.

Hubble's Wide Field Camera 3 Recovered and Collecting Science
Thu, 17 Jan 2019 14:00:00 ESTHubble Image

The Hubble Space Telescope's Wide Field Camera 3 was brought back to full operational status and completed its first science observations just after noon EST today, Jan. 17, 2019.

The Universe of Gaia - Read more >
Thu, 13 Dec 2018 16:38:00 +0100

A taste of the exciting science that is being performed using data from ESA’s Gaia star surveyor, delving into the formation history of our Milky Way

Meet ESA's science fleet - Read more >
Wed, 11 Apr 2018 13:56:00 +0200

Explore 3D models of ESA's science satellites across the Solar System in this interactive tool

This Month's Sky Map
This Month's Sky Map

Take a look at this month's Sky Map to help you explore the wonders of the night sky!

Ideal for all sky watchers including beginners to astronomy.

The Sky Map will help you identify planets, bright stars, constellations and nebulae!
Printable version available too!

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