2015/06/30

Eruption of Wolf Volcano, Galapagos Islands


In late May 2015, the highest volcano in the Galapagos Islands, Wolf volcano, erupted for the first time in 33 years. The wide image and closeup of Wolf was acquired on June 11, 2015, by the ASTER instrument on NASA's Terra satellite. The false-color images combine near-infrared, red, and green light (ASTER bands 3-2-1). via NASA http://ift.tt/1LFLHKj

2015/06/29

Spirals in the D Ring


Although the D ring of Saturn is so thin that it's barely noticeable compared to the rest of the ring system, it still displays structures seen in other Saturnian rings. via NASA http://ift.tt/1GVgmio

All the Colors of the Sun


It is still not known why the Sun's light is missing some colors. Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device. The spectrum was created at the McMath-Pierce Solar Observatory and shows, first off, that although our white-appearing Sun emits light of nearly every color, it does indeed appear brightest in yellow-green light. The dark patches in the above spectrum arise from gas at or above the Sun's surface absorbing sunlight emitted below. Since different types of gas absorb different colors of light, it is possible to determine what gasses compose the Sun. Helium, for example, was first discovered in 1870 on a solar spectrum and only later found here on Earth. Today, the majority of spectral absorption lines have been identified - but not all. via NASA http://ift.tt/1IkZVOI

2015/06/28

Stars of a Summer Triangle


Rising at the start of a northern summer's night, these three bright stars form the familiar asterism known as the Summer Triangle. Altair, Deneb, and Vega are the alpha stars of their respective constellations, Aquila, Cygnus, and Lyra, nestled near the Milky Way. Close in apparent brightness the three do look similar in these telescopic portraits, but all have their own stellar stories. Their similar appearance hides the fact that the Summer Triangle stars actually span a large range in intrinsic luminosity and distance. A main sequence dwarf star, Altair is some 10 times brighter than the Sun and 17 light-years away, while Vega, also a hydrogen-fusing dwarf, is around 30 times brighter than the Sun and lies 25 light-years away. Supergiant Deneb, at about 54,000 times the solar luminosity, lies some 1,400 light-years distant. Of course, with a whitish blue hue, the stars of the Summer Triangle are all hotter than the Sun. via NASA http://ift.tt/1Ij77Lp

2015/06/27

Planet Aurora


What bizarre alien planet is this ? It's planet Earth of course, seen through the shimmering glow of aurorae from the International Space Station. About 400 kilometers (250 miles) above, the orbiting station is itself within the upper realm of the auroral displays, also watched from the planet's surface on June 23rd. Aurorae have the signature colors of excited molecules and atoms at the low densities found at extreme altitudes. The eerie greenish glow of molecular oxygen dominates this view. But higher, just above the space station's horizon, is a rarer red band of aurora from atomic oxygen. The ongoing geomagnetic storm began after a coronal mass ejection's recent impact on Earth's magnetosphere. via NASA http://ift.tt/1J9Ei2q

2015/06/26

Watching Meteors From the Space Station


Astronaut Ron Garan tweeted this image from the International Space Station in August, 2011, writing, “What a `Shooting Star’ looks like from space, taken yesterday during Perseid Meteor Shower.” A special camera to record meteor showers will launch to the station aboard SpaceX's Dragon cargo craft, currently scheduled to launch on June 28, 2015. via NASA http://ift.tt/1BScbFu

Star Trails Above Table Mountain


Stars trail above and urban lights sprawl below in this moonlit nightscape from Cape Town, South Africa, planet Earth. The looming form of Table Mountain almost seems to hold terrestrial lights at bay while the stars circle the planet's South Celestial Pole. This modern perspective on the natural night sky was captured in June 2014, the scene composed of over nine hundred, stacked 30 second exposures. The stunning result was chosen as the winner in the Against the Lights category, a selection from over 800 entries in The World at Night's 2015 International Earth and Sky Photo Contest. via NASA http://ift.tt/1e5iHNQ

2015/06/25

Solar Dynamics Observatory Sees M7.9-Class Solar Flare


The sun emitted a mid-level solar flare, an M7.9-class, peaking at 4:16 a.m. EDT on June 25, 2015. NASA’s Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. via NASA http://ift.tt/1div2gQ

Triple Conjunction Over Galician National Park


What are those bright objects hovering over the horizon? Planets -- and the Moon. First out, the horizon featured is a shoreline of the Atlantic Ocean that occurs at the Galicia National Park in northern Spain. Next furthest out, on the left, is the Moon. Easily the brightest object on the night sky, the Moon here was in only a crescent phase. The next furthest out, on the right, is the planet Venus, while planet Jupiter is seen at the top of the triangle. The long exposure from our rapidly rotating Earth made all of celestial objects -- including the far distant stars -- appear as slight arcs. The featured image was taken last Sunday night. Although the Moon's orbit has now taken it away from this part of the sky, the planets Venus and Jupiter can be seen superposed just after sunset until mid-August. The closest apparent separation of Venus and Jupiter will occur in one week, when the two planets will appear separated by less than the angular diameter of the Moon. via NASA http://ift.tt/1fALvPa

2015/06/24

Lights of An Aurora From the International Space Station


NASA Astronaut Scott Kelly captured this photo of an aurora from the International Space Station on June 23, 2015. The dancing lights of the aurora provide spectacular views on the ground, but also capture the imagination of scientists who study incoming energy and particles from the sun. via NASA http://ift.tt/1LuBqke

Sharpless 308: Star Bubble


Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,200 light-years away toward the constellation of the Big Dog (Canis Major) and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured in the expansive image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. via NASA http://ift.tt/1NgD9aH

2015/06/23

Flying Over An Aurora


NASA astronaut Scott Kelly (@StationCDRKelly) captured photographs and video of auroras on June 22, 2015. Kelly wrote, "Yesterday's aurora was an impressive show from 250 miles up. Good morning from the International Space Station! ‪#‎YearInSpace‬" via NASA http://ift.tt/1e1NDyw

2015/06/22

Dawn Survey Orbit Image 11


A cluster of mysterious bright spots on dwarf planet Ceres can be seen in this image, taken by NASA's Dawn spacecraft from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 9, 2015. via NASA http://ift.tt/1Iu9xm9

Rings and Seasons of Saturn


On Saturn, the rings tell you the season. On Earth, today marks a solstice, the time when the Earth's spin axis tilts directly toward the Sun. On Earth's northern hemisphere, today is the Summer Solstice, the day of maximum daylight. Since Saturn's grand rings orbit along the planet's equator, these rings appear most prominent -- from the direction of the Sun -- when the Saturn's spin axis points toward the Sun. Conversely, when Saturn's spin axis points to the side, an equinox occurs and the edge-on rings are hard to see. In the featured montage, images of Saturn over the past 11 years have been superposed to show the giant planet passing from southern summer toward northern summer. Although Saturn will only reach its northern summer solstice in 2017 May, the image of Saturn most analogous to today's Earth solstice is the bottommost one. via NASA http://ift.tt/1ezyjdb

2015/06/19

Night-Shining Clouds


This image of noctilucent clouds is a composite of several Aeronomy of Ice in the Mesosphere (AIM) satellite passes over the Arctic on June 10, 2015. The clouds appear in various shades of light blue to white, depending on the density of the ice particles. The instrument measures albedo—how much light is reflected back to space by the clouds. via NASA http://ift.tt/1RgjOXB

M64: The Black Eye Galaxy


This big, bright, beautiful spiral galaxy is Messier 64, often called the Black Eye Galaxy or the Sleeping Beauty Galaxy for its heavy-lidded appearance in telescopic views. M64 is about 17 million light-years distant in the otherwise well-groomed northern constellation Coma Berenices. In fact, the Red Eye Galaxy might also be an appropriate moniker in this colorful composition. The enormous dust clouds obscuring the near-side of M64's central region are laced with the telltale reddish glow of hydrogen associated with star forming regions. But they are not this galaxy's only peculiar feature. Observations show that M64 is actually composed of two concentric, counter-rotating systems. While all the stars in M64 rotate in the same direction as the interstellar gas in the galaxy's central region, gas in the outer regions, extending to about 40,000 light-years, rotates in the opposite direction. The dusty eye and bizarre rotation is likely the result of a billion year old merger of two different galaxies. via NASA http://ift.tt/1LgCIiu

2015/06/18

Through the Clouds


On June 18, 1983, Sally Ride became the first American woman to fly in space when the space shuttle Challenger launched on mission STS-7 from Pad 39A, Kennedy Space Center. One of her jobs was to call out "Roll program" seven seconds after launch. "I'll guarantee that those were the hardest words I ever had to get out of my mouth," she said later. via NASA http://ift.tt/1K0sml0

M45: The Pleiades Star Cluster


Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as dusty as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The featured exposure took over 12 hours and covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of the Bull (Taurus). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarity of the observer's eyesight. via NASA http://ift.tt/1G2jTZJ

2015/06/17

SOFIA at Sunset


NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) takes off from Palmdale, California at sunset. SOFIA is a partnership of NASA and the German Aerospace Center (DLR); NASA and DLR have collaborated on a range of activities and signed agreements on June 16 to work together to reduce aircraft noise and advance research into rotorcraft. via NASA http://ift.tt/1CdAJDo

APOD is 20 Years Old Today


Welcome to the vicennial 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 20 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 featured image may appear similar to the whimsical Vermeer composite that ran on APOD's fifth anniversary, a perceptive eye might catch that 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. If you consider yourself a fan of APOD, you might want to consider joining the Friends of APOD. via NASA http://ift.tt/1Ca37pO

2015/06/16

Tropical Storm Bill From the International Space Station


NASA astronaut Scott Kelly, currently on a one-year mission to the International Space Station, took this photograph of Tropical Storm Bill in the Gulf of Mexico as it approached the coast of Texas, on June 15, 2015. via NASA http://ift.tt/1CbsZ4G

A Colorful Lunar Corona


What are those colorful rings around the Moon? A corona. Rings like this will sometimes appear when the Moon is seen through thin clouds. The effect is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in an intervening but mostly-transparent cloud. Since light of different colors has different wavelengths, each color diffracts differently. Lunar Coronae are one of the few quantum mechanical color effects that can be easily seen with the unaided eye. The featured lunar corona was captured around a Strawberry Moon on June 2 from La Plata, Argentina. Similar coronae that form around the Sun are typically harder to see because of the Sun's great brightness. via NASA http://ift.tt/1IF9Pt1

2015/06/15

Stars and Stripes From the International Space Station


Celebrating Flag Day on June 14, 2015, NASA astronaut Scott Kelly took this photograph in the cupola of the International Space Station. via NASA http://ift.tt/1BdxxNe

2015/06/13

The Medusa Nebula


Braided, serpentine filaments of glowing gas suggest this nebula's popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away along the southern border of the constellation Gemini. Like its mythological namesake, the nebula is associated with a dramatic transformation. The planetary nebula phase represents a final stage in the evolution of low mass stars like the sun, as they transform themselves from red giants to hot white dwarf stars and in the process shrug off their outer layers. Ultraviolet radiation from the hot star powers the nebular glow. An unrelated, bright, foreground star is near center in this close-up, telescopic view, while the Medusa's transforming central star is actually the dimmer star below center and toward the right-hand part of the frame. The Medusa Nebula is estimated to be over 4 light-years across. via NASA http://ift.tt/1S9BC9h

2015/06/12

Hubble Meeting the Neighbors


The sphere of space surrounding our galaxy is known as the Local Volume, a region some 35 million light-years in diameter and home to several hundred known galaxies. The subject of this new NASA/ESA Hubble Space Telescope image, a beautiful dwarf irregular galaxy known as PGC 18431, is one of these galaxies. via NASA http://ift.tt/1L54nTr

The Light, the Dark, and the Dusty


This colorful skyscape spans about three full moons (1.5 degrees) across nebula rich starfields along the plane of our Milky Way Galaxy in the royal northern constellation Cepheus. Near the edge of the region's massive molecular cloud some 2,400 light-years away, bright reddish emission region Sharpless (Sh) 155 lies at the upper left, also known as the Cave Nebula. About 10 light-years across the cosmic cave's bright rims of gas are ionized by ultraviolet light from hot young stars. Dusty blue reflection nebulae also abound on the interstellar canvas cut by dense obscuring clouds of dust. The long core of the Lynds Dark Nebula (LDN) 1210 anchors the scene at lower right. Astronomical explorations have revealed other dramatic signs of star formation, including the bright red fleck of Herbig-Haro (HH) 168. Directly below the bright Cave Nebula, the Herbig-Haro object emission is generated by energetic jets from a newborn star. via NASA http://ift.tt/1KrqKkE

2015/06/11

Expedition 43 Soyuz Landing


The Soyuz TMA-15M spacecraft is seen as it lands with Expedition 43 commander Terry Virts of NASA, cosmonaut Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos), and Italian astronaut Samantha Cristoforetti from the European Space Agency (ESA) near the town of Zhezkazgan, Kazakhstan on Thursday, June 11, 2015. via NASA http://ift.tt/1Kwxw90

2015/06/10

Lonely Galaxy Lost in Space


This galaxy, known as NGC 6503, has found itself in a lonely position, at the edge of a strangely empty patch of space called the Local Void. via NASA http://ift.tt/1KVKpau

Galaxy NGC 7714 After Collision


Is this galaxy jumping through a giant ring of stars? Probably not. Although the precise dynamics behind the featured image is yet unclear, what is clear is that the pictured galaxy, NGC 7714, has been stretched and distorted by a recent collision with a neighboring galaxy. This smaller neighbor, NGC 7715, situated off to the left of the featured frame, is thought to have charged right through NGC 7714. Observations indicate that the golden ring pictured is composed of millions of older Sun-like stars that are likely co-moving with the interior bluer stars. In contrast, the bright center of NGC 7714 appears to be undergoing a burst of new star formation. NGC 7714 is located about 100 million light years away toward the constellation of the Fish (Pisces). The interactions between these galaxies likely started about 150 million years ago and should continue for several hundred million years more, after which a single central galaxy may result. via NASA http://ift.tt/1T8n1wh

2015/06/09

Tethys the Target


Like most moons in the solar system, Tethys is covered by impact craters. Some craters bear witness to incredibly violent events, such as the crater Odysseus (seen here at the right of the image). The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 11, 2015. via NASA http://ift.tt/1B0azJc

The Milky Way over the Temple of Poseidon


What's that glowing in the distance? Although it may look like a lighthouse, the rays of light near the horizon actually emanate from the Temple of Poseidon at Cape Sounion, Greece. Some temple lights are even reflected in the Aegean Sea in the foreground. Although meant to be a monument to the sea, in this image, the temple's lights seem to be pointing out locations on the sky. For example, the wide ray toward the right fortuitously points toward the Lagoon Nebula in the central band of our Milky Way, which runs diagonally down the image from the upper left. Also, the nearly vertical beam seems to point toward the star clouds near the direction of the Wild Duck open cluster of stars. The featured image was taken less than three weeks ago. via NASA http://ift.tt/1AVXgK2

2015/06/08

Samantha Cristoforetti Prepares For the Journey Home


ESA astronaut Samantha Cristoforetti checks her Sokol pressure suit in preparation for the Expedition 43 crew's departure from the International Space Station after 6 1/2 months in space. Cristoforetti now holds the record for the longest single spaceflight for a woman, a record previously held by NASA astronaut Sunita Williiams. via NASA http://ift.tt/1RYsEf5

NGC 3132: The Eight Burst Nebula


It's the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula. Nicknamed the Eight-Burst Nebula and the Southern Ring Nebula, the glowing gas originated in the outer layers of a star like our Sun. In this representative color picture, the hot blue pool of light seen surrounding this binary system is energized by the hot surface of the faint star. Although photographed to explore unusual symmetries, it's the asymmetries that help make this planetary nebula so intriguing. Neither the unusual shape of the surrounding cooler shell nor the structure and placements of the cool filamentary dust lanes running across NGC 3132 are well understood. via NASA http://ift.tt/1QB5I2W

2015/06/07

Into the Void


Fifty years ago, on June 3, 1965, Edward White stepped out of the orbiting Gemini 4 spacecraft to become the first US astronaut to walk in space. White is captured in this photo taken by mission commander James McDivit from inside the capsule as White's spacewalk began over the Pacific Ocean on Gemini 4's third orbit. Planet Earth, spacecraft, and tether are reflected in White's gold tinted helmet visor. A gas powered manuevering gun is held in his right hand. Though the gun ran out of gas after only 3 minutes, he continued to manuever by twisting his body and pulling on the tether for the remainder of the 23 minute long Extra Vehicular Activity. White later described his historic spacewalk as the most comfortable part of the mission, and said the order to end it was the "saddest moment" of his life. via NASA http://ift.tt/1AQvP48

2015/06/06

Green Flash at Moonrise


Follow a sunset on a clear day against a distant horizon and you might glimpse a green flash just as the Sun disappears, the sunlight briefly refracted over a long sight-line through atmospheric layers. You can spot a green flash at sunrise too. Pinpointing the exact place and time to see the rising Sun peeking above the horizon is a little more difficult though, and it can be harder still to catch a green flash from the fainter rising Moon. But well-planned snapshots did record a green flash at the Full Moon's upper edge on June 2nd, from the Roque de los Muchachos Observatory on the Canary Island of La Palma. Looking a little south of due east, this long telephoto view finds the rising Moon above mountains and a sea of clouds. In sunlit profile are the mountaintop Teide Observatory telescope domes on the island of Tenerife some 143 kilometers away. via NASA http://ift.tt/1MrUcWV

2015/06/05

Fresh Crater Near Sirenum Fossae Region of Mars


The HiRISE camera aboard NASA's Mars Reconnaissance Orbiter acquired this closeup image of a "fresh" (on a geological scale, though quite old on a human scale) impact crater in the Sirenum Fossae region of Mars on March 30, 2015. This impact crater appears relatively recent as it has a sharp rim and well-preserved ejecta. via NASA http://ift.tt/1H8Lm0g

NGC 2419: Intergalactic Wanderer


Three objects stand out in this thoughtful telescopic image, a view toward the mostly stealthy constellation Lynx. The two brightest (the spiky ones) are nearby stars. The third is the remote globular star cluster NGC 2419, at distance of nearly 300,000 light-years. NGC 2419 is sometimes called "the Intergalactic Wanderer", an appropriate title considering that the distance to the Milky Way's satellite galaxy, the Large Magellanic Cloud, is only about 160,000 light-years. Roughly similar to other large globular star clusters like Omega Centauri, NGC 2419 is itself intrinsically bright, but appears faint because it is so far away. NGC 2419 may really have an extragalactic origin as, for example, the remains of a small galaxy captured and disrupted by the Milky Way. But its extreme distance makes it difficult to study and compare its properties with other globular clusters that roam the halo of our Milky Way galaxy. via NASA http://ift.tt/1Q8BcSQ

2015/06/04

June 4, 1965, Earth Observations From Gemini IV


This photograph of the Florida Straits and Grand Bahama Bank was taken during the Gemini IV mission during orbit no. 19, on June 4, 1965. The Gemini IV crew conducted scientific experiments, including photography of Earth's weather and terrain, for the remainder of their four-day mission following Ed White's historic spacewalk on June 3. via NASA http://ift.tt/1czMbCq

Flyby Image of Saturns Sponge Moon Hyperion


Why does this moon look like a sponge? To better investigate, NASA and ESA sent the Saturn-orbiting robotic spacecraft Cassini zooming past Saturn's moon Hyperion, once again, earlier this week. One of the images beamed back to Earth is featured above, raw and unprocessed. Visible, as expected, are many unusually shaped craters with an unusual dark material at the bottom. Although Hyperion spans about 250 kilometers, its small gravitational tug on Cassini indicates that it is mostly empty space and so has very low surface gravity. Therefore, the odd shapes of many of Hyperion's craters are thought to result from impacts that primarily compress and eject surface material -- instead of the more typical round craters that appear after a circular shock wave that explosively redistributes surface material. Cassini is on track for another flyby of Saturn's Dione in about two weeks. via NASA http://ift.tt/1FrXpjD

2015/06/03

NASA Celebrates 50 Years of Spacewalking


For 50 years, NASA has been "suiting up" for spacewalking. In this Feb. 7, 1984 photograph of the first untethered spacewalk, NASA astronaut Bruce McCandless is in the midst of the first "field" tryout of a nitrogen-propelled backpack device called the Manned Maneuvering Unit (MMU). via NASA http://ift.tt/1K9NJRo

Polaris and Comet Lovejoy


One of these two bright sky objects is moving. On the right is the famous star Polaris. Although only the 45th brightest star in the sky, Polaris is famous for appearing stationary. Once you find it, it will always appear in the same direction -- all night and all day -- for the rest of your life. This is because the northern spin pole of the Earth -- called the North Celestial Pole -- points near Polaris. On the left, about ten million times closer, is Comet Lovejoy, which noticeably changes its sky position by the hour. The featured image was taken last week. Officially designated C/2014 Q2 (Lovejoy), this disintegrating snowball is on a visit from the outer Solar System and will only appear near the North Star for a few more weeks. That should be long enough, however, for northerners with binoculars or a small telescope to see the greenish coma of this fleeting newcomer, perhaps with the help of a good star map. via NASA http://ift.tt/1dbap6t

2015/06/02

Shadow of Surveyor 1 on the Moon


Surveyor 1, the first of the Surveyor missions to make a successful soft landing, proved the validity of the spacecraft's design and landing technique. In addition to transmitting more than 11,000 pictures, Surveyor sent information on the bearing strength of the lunar soil, the radar reflectivity and temperature. via NASA http://ift.tt/1I9sRr5

2015/06/01

Low-Density Supersonic Decelerator Prepared For Second Flight Test


The second flight test of NASA's Low-Density Supersonic Decelerator (LDSD) will be attempted on Tuesday, June 2, launching a rocket-powered, saucer-shaped test vehicle into near-space from the Pacific Missile Range Facility on the island of Kauai in Hawaii. At launch time, a giant balloon will carry the test vehicle to an altitude of 120,000 feet. via NASA http://ift.tt/1ctFqSv

Supernova 1994D and the Unexpected Universe


Long ago, far away, a star exploded. Supernova 1994D, visible as the bright spot on the lower left, occurred in the outskirts of disk galaxy NGC 4526. Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae. In fact, the light emitted during the weeks after its explosion caused it to be given the familiar designation of a Type Ia supernova. If all Type 1a supernovae have the same intrinsic brightness, then the dimmer a supernova appears, the farther away it must be. By calibrating a precise brightness-distance relation, astronomers are able to estimate not only the expansion rate of the universe (parameterized by the Hubble Constant), but also the geometry of the universe we live in (parameterized by Omega and Lambda). The large number and great distances to supernovae measured over the past few years, when combined with other observations, are interpreted as indicating that we live in a previously unexpected universe. via NASA http://ift.tt/1FLWxty