Happy Anniversary, APOD!
Image Credit & Copyright: Judy Schmidt
The first APOD appeared seventeen years ago today, on 1995 June 16. Although garnering only 14 page views on that day, we are proud to estimate that APOD has now served over one billion space-related images over the last 1.7 decades. That early beginning, along with a nearly unchanging format, has allowed APOD to be a consistent and familiar site on a web frequently filled with change. Many people don't know, though, that APOD is now translated daily into many major languages and featured on social media sites and smartphone applications. We again thank our readers and NASA for their continued support, as well as the folks who created the great pictures -- many times with considerable effort -- that APOD has been fortunate enough to feature over the years. Many can be contacted by following links found in the credit line under the image. Today's birthday collage includes numerous galaxies captured by the Hubble Space Telescope.
The robotic MESSENGER spacecraft recently completed over 100 orbits of Mercury. MESSENGER's cameras have recorded detailed pictures utilizing eight different colors across visible and near infrared light, exploring the surface composition and looking for clues to the history and evolution of the solar system's innermost planet. This sharp image combines three of the MESSENGER wide angle camera's colors, but in exaggerated fashion. Otherwise, to the unaided human eye, Mercury's surface colors would appear comparatively muted. The image is about 1,000 kilometers across and features as small as a single kilometer are discernible at the original resolution. Today, the MESSENGER project will release new images and science findings from the first spacecraft to orbit Mercury.
Image Pixelation: Rob StevensonApologies to: Vermeer's Astronomer and Geographer;
Welcome to the quindecennial year of the Astronomy Picture of the Day! Perhaps a source of web consistency for some, APOD is still here. As during each of the 15 years of selecting images, writing text, and editing the APOD web pages, the occasionally industrious Robert Nemiroff (left) and frequently persistent Jerry Bonnell (right) are pictured above plotting to highlight yet another unsuspecting image of our cosmos. Although the above image may appear similar to the whimsical Vermeer composite that ran on APOD's fifth anniversary, a perceptive eye might catch that this year it has been digitally re-pixelated using many of the over 5,000 APOD images that have appeared over APOD's tenure. (Can you find any notable APOD images?) Once again, we at APOD would like to offer a sincere thank you to our readership for continued interest, support, and many gracious communications.
On the occasion of our 14th anniversaryCredit & Copyright: Tahir Sisman
Is the Moon larger when near the horizon? No -- as shown above, the Moon appears to be very nearly the same size no matter its location on the sky. Oddly, the cause or causes for the common Moon Illusion are still being debated. Two leading explanations both hinge on the illusion that foreground objects make a horizon Moon seem farther in the distance. The historically most popular explanation then holds that the mind interprets more distant objects as wider, while a more recent explanation adds that the distance illusion may actually make the eye focus differently. Either way, the angular diameter of the Moon is always about 0.5 degrees. In the above time-lapse sequence of the Moon taken in 2007, with one exposure taken to bring up the foreground of Izmit Bay in Turkey. On the occasion of our 14th anniversary, the APOD editors thank all of our contributors and mirror site operators whose volunteer efforts help bring the wonders of astronomy to millions of people around the world. Additional thanks also go to our Turkish mirror site operators for submitting the above mouseover image.
Almost every object in the above photograph is a galaxy. The Coma Cluster of Galaxies pictured above is one of the densest clusters known - it contains thousands of galaxies. Each of these galaxies houses billions of stars - just as our own Milky Way Galaxy does. Although nearby when compared to most other clusters, light from the Coma Cluster still takes hundreds of millions of years to reach us. In fact, the Coma Cluster is so big it takes light millions of years just to go from one side to the other! The above mosaic of images of a small portion of Coma was taken in unprecedented detail by the Hubble Space Telescope to investigate how galaxies in rich clusters form and evolve. Most galaxies in Coma and other clusters are ellipticals, although some imaged here are clearly spirals. The spiral galaxy on the upper left of the above image can also be found as one of the bluer galaxies on the upper left of this wider field image. In the background thousands of unrelated galaxies are visible far across the universe.
To prepare for the Apollo landings, five Lunar Orbiter spacecraft were launched during 1966 and 1967 to gather detailed images of our fair planet's large, natural satellite. Dramatic views returned by the spacecraft cameras included this stark moonscape. The mosaic of 93 kilometer wide impact crater Copernicus features central peaks rising above the crater floor and rugged crater walls.Note: As of today, June 16, the APOD editors have enjoyed presenting images from space missions, major observatories, and professional and amateur cosmic tourists alike for twelve years. A sincere thanks to our web site operators, translators, and to all for the gracious email and continued APOD submissions!
The first APOD appeared eleven years ago today, on 1995 June 16. Although garnering only 14 page views on that day, we are proud to estimate that APOD has now served over 400 million space-related images over the last eleven years. That early beginning, along with a nearly unchanging format, has allowed APOD to be a consistent and familiar site on a web frequently filled with change. Many people don't know, though, that APOD is now translated daily into many major languages. We again thank our readers and NASA for their continued support, but ask that any potentially congratulatory e-mail go to the folks who created the great pictures -- many times with considerable effort -- that APOD has been fortunate enough to feature over the past year. Many can be contacted by following links found in the credit line under the image. Some of these images are featured in the above spectacular collage of a fantasy sky above Mars submitted by an enthusiastic APOD reader skilled in digital image manipulation. How many APOD images can you identify?
Welcome to the eleventh year of Astronomy Picture of the Day! In a decade of editing the APOD web pages, the industrious Robert Nemiroff (left) and persistent Jerry Bonnell (right) have enjoyed exploring compelling images of the cosmos that are not limited to those taken from earth orbit, much less to those taken by professional astronomers. In fact, seen in this recently released Vermeer, the editors are extremely grateful for the continued large volume of gracious e-mail and APOD submissions. Today, they would like to offer a sincere thank you to all. And while these APOD editors are definitely not getting any younger, tomorrow's picture may actually be ...
Elliptical galaxy M87 is a type of galaxy that looks much different than our own Milky Way Galaxy. Even for an elliptical galaxy, though, M87 is peculiar. M87 is much bigger than an average galaxy, appears near the center of a whole cluster of galaxies known as the Virgo Cluster, and shows an unusually high number of globular clusters. These globular clusters are visible as faint spots surrounding the bright center of M87. In general, elliptical galaxies contain similar numbers of stars as spiral galaxies, but are ellipsoidal in shape (spirals are mostly flat), have no spiral structure, and little gas and dust. The above image of M87 was taken recently by the Canada-France-Hawaii Telescope on top of the dormant volcano Mauna Kea in Hawaii, USA.
The first APOD appeared eight years ago today, on 1995 June 16. To date, we estimate that APOD has now served over 100 million space-related images. We again thank our readers and NASA for their continued support, but ask that any potentially congratulatory e-mail go to the folks who created the great pictures -- many times with considerable effort -- that APOD has been fortunate enough to feature over the past year. Many can be contacted by following links found in the credit line under the image. Some of these images are featured in the above spectacular collage submitted by an enthusiastic APOD reader well skilled in digital image manipulation. She challenges fellow APODees to find in the collage her favorite ex-member of the musical group Tangerine Dream.
Why does Jupiter have rings? Jupiter's rings were discovered in 1979 by the passing Voyager 1 spacecraft, but their origin was a mystery. Data from the Galileo spacecraft currently orbiting Jupiter later confirmed that these rings were created by meteoroid impacts on small nearby moons. As a small meteoroid strikes tiny Adrastea, for example, it will bore into the moon, vaporize, and explode dirt and dust off into a Jovian orbit. Pictured above is an eclipse of the Sun by Jupiter, as viewed from Galileo. Small dust particles high in Jupiter's atmosphere, as well as the dust particles that compose the rings, can be seen by reflected sunlight.
Welcome to the seventh year of Astronomy Picture of the Day (APOD). Editors Robert Nemiroff and Jerry Bonnell are extremely grateful for the continued large volume of gracious e-mail and APOD submissions (and also for the "occasional" critical note!). Today we would like to offer a very sincere thank you to all. We are certainly proud that each day over the last six years APOD has consistently coupled an expanding universe of hypertext with inspiring images of the cosmos. In fact, tomorrow's picture might actually be ...
Welcome to the sixth year of Astronomy Picture of the Day (APOD)! Above are the industrious Robert Nemiroff (left) and persistent Jerry Bonnell (right), still engaged in creating the APOD web pages. As suggested by imagery in this recently released Vermeer, APOD's origins derive from many dramatic, intellectual deliberations over the ultimate value of the World Wide Web. In our view, the WWW has evolved into a significant and still growing collective human resource and we think it's important to contribute. We are extremely grateful for the continued large volume of gracious e-mail and APOD submissions. Today we would like to offer a very sincere thank you to all. We are certainly proud that each day over the last five years APOD has consistently coupled an expanding universe of hypertext with inspiring images of the cosmos. In fact, tomorrow's picture might actually be ...
Sometimes lightning occurs out near space. One such lightning type is the recently documented red sprite lightning, which has only been photographed and studied on Earth over the last few years. The origins of all types of lightning remains unknown, and scientists are even trying to figure out why red sprite lightning occurs at all. What is known is that as some large, positive cloud-to-ground lightning strokes occur, millisecond flashes appearing red may also occur far above in the upper atmosphere. Pictured above, a group of red sprites was photographed at high resolution. Reasons for the observed complexities are being researched.
The Sun is a busy place. This false-color image depicts an active region near an edge of the Sun. Hot plasma is seen exploding off the Sun's photosphere and traveling along loops defined by the Sun's magnetic field. The red regions are particularly hot, indicating that some magnetic field loops carry hotter gas than others. These active loops were so large that the Earth could easily fit under one. The TRACE satellite was launched in April with plans to continue high-resolution imaging as the Sun passes Solar Maximum in the next few years.
The first Astronomy Picture of the Day (APOD) appeared two years ago today. Pictured above is a scene surrounding the creation of an early APOD, depicting the famous astronomer Tycho Brahe demonstrating a celestial globe to Emperor Rudolph II. The image of a possible optical counterpart to a gamma-ray burst appears on the back wall. In Tycho's day, humanity discovered the nature of the Earth and the geometry of the Solar System. The times we live in are even more fascinating as we explore the nature of our Solar System and the geometry of our whole universe. APOD continues to chronicle these events by finding, presenting ,and annotating the most important astronomical pictures of our time, and cataloging them in an indexed and searchable archive. Link to APOD and discover the cosmos! With over five million pages served, we thank NASA, Michigan Tech, USRA, and most of all our readers, for their continued support.
The first Astronomy Picture of the Day (APOD) appeared one year ago today. Pictured above are Robert Nemiroff (left) and Jerry Bonnell (right), engaged in creating the APOD web pages. APOD started over speculative conversations on the ultimate value of the World Wide Web. In our (current) view, the WWW is the closest thing yet to an "Encyclopedia of Humanity," and we think it's important to contribute. We are proud to say that APOD has now annotated most of the famous astronomical pictures of our time and has made them available to the general public in an indexed and searchable archive. During it's first year, APOD's main daily picture page has been served over one million times. But APOD's mission continues. As space science progresses more pictures, fresh insights, and new educative links become available. Therefore, so long as public interest and NASA support continue, APOD will continue. We thank all whose gracious e-mail are continually a source of encouragement.
If the Earth could somehow be transformed to the ultra-high density of a neutron star , it might appear as it does in the above computer generated figure. Due to the very strong gravitational field, the neutron star distorts light from the background sky greatly. If you look closely, two images of the constellation Orion are visible. The gravity of this particular neutron star is so great that no part of the neutron star is blocked from view - light is pulled around by gravity even from the back of the neutron star.