30 Years of City Growth Seen From Space

China's now-industrialized Pearl River Delta, seen in October 1973 (top) and January 2003 (bottom)

Since the launch of its first satellite in 1972, the eight NASA/USGS Landsat satellites have made the longest continuous observations of Earth’s surface, providing invaluable data for research in agriculture, geology, forestry, regional planning, education, mapping, global change research, as well as important emergency response and disaster relief information. In addition, having such a long span of data allows us to easily see the expansion of human development in many areas — unprecedented before-and-after views of city growth seen from space.

These images, taken over the course of the Landsat program, illustrate the visible impact of over three decades of human development:

Chandler, Arizona imaged in 1985 (top) and 2011 (bottom.)  As its economy shifted from agriculture to manufacturing and electronics, Chandler's population multiplied 8 times to over 236,000.
Chandler, Arizona imaged in 1985 (top) and 2011 (bottom.) As its economy shifted from agriculture to manufacturing and electronics, Chandler’s population multiplied 8 times to over 236,000.
The explosion of Istanbul's population from 2 to 3 million people is evident in these Landsat images, comparing 1975 to 2011. Vegetation appears red in the imaging wavelengths used here.
The explosion of Istanbul’s population from 2 to 13 million people is evident in these Landsat images, comparing 1975 to 2011. Vegetation appears red in the imaging wavelengths used here.
A few years ago one of the fastest-growing cities in the US, Las Vegas is seen here in images taken in 1984 (top) and 2011 (bottom.) The sprawling development -- as well as the decrease in water level of Lake Mead -- is evident.
A few years ago one of the fastest-growing cities in the US, Las Vegas is seen here in images taken in 1984 (top) and 2011 (bottom.) The sprawling development — as well as the decrease in water level of Lake Mead — is evident.
Some of the most dramatic -- and rapid --  changes have occurred in Dubai, whose artificial offshore islands suddenly appear between images taken in 2000 (top) and 2010 (bottom.) Once barely visible against the desert landscape, Dubai is now an international center of business, tourism, and oil production.
Some of the most dramatic — and rapid — changes have occurred in Dubai, whose palm- and continent-shaped artificial islands suddenly appear between images taken in 2000 (top) and 2010 (bottom.) Once barely visible against the desert landscape, Dubai is now an international center of business, tourism, and oil production.

See more of these images on NASA Goddard Space Flight Center’s Flickr album here.

The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey. In 1972, the launch of ERTS-1 (Earth Resources Technology Satellite, later renamed Landsat 1) started the era of a series of satellites that have since continuously acquired space-based land remote sensing data.

The latest satellite in the Landsat series, the Landsat Data Continuity Mission (LDCM) — now named Landsat 8 — was launched on February 11, 2013. Landsat 8 data is now available free to the public online here.

Read more on the USGS Landsat mission page here.

Image credits: USGS/NASA

Podcast: Sound in Space

Shhhh, shhh. You can stop screaming. That’s because nobody can hear you … in space. But why not? How does sound work here on Earth, and what would it sound like on other planets?

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Sound” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout (usually recorded every Monday at 3 pm Eastern Time):

Whimsical and Beautiful New Timelapse: Borrego Stardance

A still from the new timelapse, 'Borrego Stardance' by Gavin Heffernan/Sunchaser Pictures.

Just outside of Borrego Springs, California, monsters lurk. Life-size metal statues of dinosaurs, dragons, and wooly mammoths stand among giant insects, birds and several other creatures. But the 600,000 acre Anzo-Borrego State Park is also an astronomer’s dream, since it is one of four communities in the world to be classified a “Dark Sky Community” by the International Dark Sky Association.

Timelapse maven Gavin Heffernan from Sunchaser Pictures has now combined these monsters and the beautiful dark sky for his latest astronomical timelapse video, Borrego Stardance. It’s an unusual and fanciful look at the night sky –- where else can you see dragons and star trails at the same time? Watch below — and crank the volume for added effect!

“Despite the grueling 112 degree temperatures, my team and I had an amazing shoot, with some of the clearest Milky Way footage we’ve ever captured” Gavin wrote Universe Today via email, “as well as some exciting creature-filled star trails, and more experiments with “Starscaping” (switching from stars to trails mid-shot).”

It’s a beautiful addition to Gavin’s already impressive timelapse and video collection. You can see a behind-the-scenes video of the Borrego site here.

You can find more information on the statues at the Galleta Meadows website.

BORREGO STARDANCE from Sunchaser Pictures on Vimeo.

Astronomers See Snow … In Space!

Artist's conception of the snow line in TW Hydrae. Credit: Bill Saxton/Alexandra Angelich, NRAO/AUI/NSF

There’s an excellent chance of frost in this corner of the universe: astronomers have spotted a “snow line” in a baby solar system about 175 light-years away from Earth. The find is cool (literally and figuratively) in itself. More importantly, however, it could give us clues about how our own planet formed billions of years ago.

“[This] is extremely exciting because of what it tells us about the very early period in the history of our own solar system,” stated Chunhua Qi, a researcher with the Harvard-Smithsonian Center for Astrophysics who led the research.

“We can now see previously hidden details about the frozen outer reaches of another solar system, one that has much in common with our own when it was less than 10 million years old,” he added.

The real deal enhanced-color picture of TW Hydrae is below, courtesy of a newly completed telescope: the Atacama Large Millimeter/submillimeter Array in Chile. It is designed to look at grains and other debris around forming solar systems. This snow line is huge, stretching far beyond the equivalent orbit of Neptune in our own solar system. See the circle? That’s Neptune’s orbit. The green stuff is the snow line. Look just how far the green goes past the orbit.

The carbon monoxide line as seen by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The circle represents the equivalent orbit of Neptune when comparing it to our own solar system. Credit: Karin Oberg, Harvard University/University of Virginia
The carbon monoxide line on TW Hydrae as seen by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The circle represents the equivalent orbit of Neptune when comparing it to our own solar system. Credit: Karin Oberg, Harvard University/University of Virginia

Young stars are typically surrounded by a cloud of gas and debris that, astronomers believe, can in many cases form into planets given enough time. Snow lines form in young solar systems in areas where the heat of the star isn’t enough to melt the substance. Water is the first substance to freeze around dust grains, followed by carbon dioxide, methane and carbon monoxide.

It’s hard to spot them: “Snow lines form exclusively in the relatively narrow central plane of a protoplanetary disk. Above and below this region, stellar radiation keeps the gases warm, preventing them from forming ice,” the astronomers stated. In areas where dust and gas are more dense, the substances are insulated and can freeze — but it’s difficult to see the snow through the gas.

In this case, astronomers were able to spot the carbon monoxide snow because they looked for diazenylium, a molecule that is broken up in areas of carbon monoxide gas. Spotting it is a “proxy” for spots where the CO froze out, the astronomers said.

Here are some more of the many reasons this is exciting to astronomers:

  • Snow could help dust grains form faster into rocks and eventually, planets because it coats the grain surface into something more stickable;
  • Carbon monoxide is a requirement to create methanol, considered a building block of complex molecules and life;
  • The snow was actually spotted with only a small portion of ALMA’s 66 antennas while it was still under construction. Now that ALMA is complete, scientists are already eager to see what the telescope will turn up the next time it gazes at the system.

Source: National Radio Astronomy Observatory

 

Carnival of Space #312

This week’s Carnival of Space is hosted by Stefan Lamoureux at his Links Through Space blog.

Click here to read Carnival of Space #312.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

Zogg From Betelgeuse Explains Why the Universe Has No Edge

Trying to explain the topology of the Universe is really complicated… for humans. But it clearly comes naturally to Zogg the Alien from Betelgeuse. In this 10-minute video, the plucky alien vividly describes how we could have a Universe which is flat and finite, but doesn’t have an edge. How we could travel in one direction and return to our starting point, never bumping into the outside of the Universe.

What is the Universe expanding into? Nothing, it’s just expanding.

Dig a little further through Zogg’s YouTube channel, and you’ll see a great collection of explainers on eating, vision; and even esoteric topics like imagination and beauty.

I’d love to see more in this series Zogg… hint, hint.

A Weird West Tale and the Hunt for Planet Vulcan

A hypothetical Vulcanoid asteroid in orbit about the Sun. ( Artist's impression in the Public Domain).

One of the most fascinating stories in modern astronomy involves the pursuit of a world that never was.

Tomorrow marks the 135th anniversary of the total solar eclipse of July 29th, 1878. With a maximum totality of 3 minutes 11 seconds, this eclipse traced a path across western Canada and the United States from the territory of Montana to Louisiana.

A curious band of astronomers also lay in wait along the path of totality, searching for an elusive world known as Vulcan.

Long before Star Trek or Mr. Spock, Vulcan was a hypothetical world thought to inhabit the region between the planet Mercury and the Sun.

The tale of Vulcan is the story of the birth of modern predictive astronomy. Vulcan was a reality to 18th century astronomers- it can be seen and the astronomy textbooks and contemporary art and culture of the day. Urbain J.J. Le Verrier proposed the existence of the planet in 1859 to explain the anomalous precession of the perihelion of the planet Mercury. Le Verrier was a voice to be taken seriously — he had performed a similar feat of calculation to lead observers to the discovery of the planet Neptune from the Berlin Observatory on the night of September 23, 1846. Almost overnight, Le Verrier had single-handedly boosted astronomy into the realm of a science with real predictive power.

An 1863 photograph of Lescarbault's country house observatory. (Wikimedia Commons image in the public domain).
An 1863 photograph of Lescarbault’s country house observatory. (Wikimedia Commons image in the public domain).

The idea of Vulcan gained traction when a French doctor and amateur astronomer Edmond Lescarbault claimed to have seen the tiny world transit the Sun while viewing it through his 95 millimetre refractor on the sunny afternoon of March 26th, 1859. Keep in mind, this was an era when solar observations were carried out via the hazardous method of viewing the Sun through a smoked or oil-filled filter, or the via safer technique of projecting the disk and sketching it onto a piece of paper.

A early right-angle solar viewer from the South Carolina State Museum in Columbia, South Carolina. Note the vent holes in the back to disappate heat and word SUN stenciled on the side! (Photo by author).
A early right-angle solar viewer from Robert Ariail collection at the South Carolina State Museum in Columbia, South Carolina. Note the vent holes in the back to dissipate heat, and word SUN stenciled on the side! (Photo by author).

A visiting Le Verrier was sufficiently impressed by Lescarbault’s observation, and went as far as to calculate and publish orbital tables for Vulcan. Soon, astronomers everywhere were “seeing dots” pass in front of the Sun. Astronomer F. A. R. Russell spotted an object transiting the Sun from London on January, 29th, 1860. Sightings continued over the decades, including a claim by an observer based near Peckeloh Germany to have witnessed a transit of Vulcan on April 4th, 1876.

Incidentally, we are not immune to this effect of “contagious observations” even today — for example, when Comet Holmes brightened to naked eye visibility in October 2007, spurious reports of other comets brightening flooded message boards, and a similar psychological phenomena occurred after amateur astronomer Anthony Wesley recorded an impact on Jupiter in 2010. Though the event that triggered the initial observation was real, the claims of impacts on other bodies in the solar system that soon followed turned out to be bogus.

Possible "target zone" for the existence of Vulcan, and later Vulcanoid asteroids.
Possible “target zone” for the existence of Vulcan, and later Vulcanoid asteroids. (Graphic in the public domain).

Still, reports of the planet Vulcan were substantial enough for astronomers to mount an expedition to the territory of Wyoming in an attempt to catch dim Vulcan near the Sun during the brief moments of totality. Participants include Simon Newcomb of the Naval Observatory, James Craig Watson and Lewis Swift. Inventor Thomas Edison was also on hand, stationed at Rawlins, Wyoming hoping to test his new-fangled invention known as a tasimeter to measure the heat of the solar corona.

Conditions were austere, to say the least. Although the teams endured dust storms that nearly threatened to cut their expeditions short, the morning of the 29th dawned, as one newspaper reported, “as slick and clean as a Cheyenne free-lunch table.” Totality began just after 4 PM local, as observers near the tiny town of Separation, Wyoming swung their instruments into action.

Such a quest is difficult under the best of circumstances. Observers had to sweep the area within 3 degrees of the Sun (six times the diameter of a Full Moon) quickly during the fleeting moments of totality with their narrow field refractors, looking for a +4th magnitude star or fainter among the established star fields.

Map of the path of the total solar eclipse of July 29th, 1878. (Credit: Fred Espenak/NASA/GSFC).
Map of the path of the total solar eclipse of July 29th, 1878. (Credit: Fred Espenak/NASA/GSFC).

In the end, the expedition was both a success and a failure. Watson & Swift both claimed to have identified a +5th magnitude object similar in brightness to the nearby star Theta Cancri. Astronomer Christian Heinrich Friedrich Peters later cast doubt on the sighting and the whole Vulcan affair, claiming  that “I refuse to go on a wild goose chase after Le Verrier’s mythical birds!”

And speaking of birds, Edison ran into another eclipse phenomenon while testing his device, when chickens, fooled by the approaching false dusk came home to roost at the onset of totality!

Vulcan search map for the Smithsonian Obervatory's 1900 eclipse expedition. (From the collection of Michael Zeiler @EclipseMaps, used with permission).
Vulcan search map for the Smithsonian Observatory’s 1900 eclipse expedition. (From the collection of Michael Zeiler @EclipseMaps, used with permission).

But such is the life of an eclipse-chaser. Albert Einstein’s general theory of relativity explained the precession of Mercury’s orbit in 1916 and did away with a need for Vulcan entirely.

But is the idea of intra-Mercurial worldlets down for the count?

The search strategy for NASA's high-altitude mission to hunt for Vulcanoids in 2002. (Credit: NASA/Dryden).
The search strategy for NASA’s high-altitude mission to hunt for Vulcanoids in 2002. (Credit: NASA/Dryden).

Amazingly, the quest for objects inside Mercury’s orbit goes on today, and the jury is still out. Dubbed Vulcanoids, modern day hunters still probe the inner solar system for tiny asteroids that may inhabit the region close to the Sun. In 2002, NASA conducted a series of high altitude flights out of the Dryden Flight Research Center at Edwards Air Force Base, California, sweeping the sky near the Sun for Vulcanoids at dawn and dusk. Now, there’s a job to be envious of — an F-18 flying astronomer!

One of NASA's fleet of high-performance F-18 aircraft. (Credit: NASA).
One of NASA’s fleet of high-performance F-18 aircraft. (Credit: NASA).

NASA’s MESSENGER spacecraft was also on the lookout for Vulcanoids on its six year trek through the inner solar system prior to orbital insertion on March 18th, 2011.

Thus far, these hunts have turned up naught. But one of the most fascinating quests is still ongoing and being carried out by veteran eclipse-chaser Landon Curt Noll.

Mr. Noll last conducted a sweep for Vulcanoids during total phases of the long duration total solar eclipse of July 22nd, 2009 across the Far East. He uses a deep sky imaging system, taking pictures in the near-IR to accomplish this search. Using this near-IR imaging technique during a total solar eclipse requires a stable platform, and thus performing this feat at sea or via an airborne platform is out. Such a rig has been successful in catching the extremely thin crescent Moon at the moment it reaches New phase.

Libya
Mr. Noll explains the aspects of an eclipse during a 2006 expedition to Libya. (Coutesy of Landon Curt Noll, used with permission).

To date, no convincing Vulcanoid candidates have been found.  Mr. Noll also notes  that the European Space Agency/NASA’s joint Solar Heliospheric Observatory (SOHO) spacecraft has, for all intents and purposes, eliminated the possibility of Vulcanoids brighter than +8th magnitude near the Sun. Modern searches during eclipses conducted in this fashion scan the sky between wavelengths of 780 to 1100 nanometres down to magnitude +13.5. Mr. Noll told Universe Today that “Our improved orbital models show that objects as small as 50m in diameter could reside in a zone 0.08 A.U. to 0.18 AU (1.2 to 2.7 million kilometers) from the Sun.” He also stated that, “there is plenty of ‘room’ for (Vulcanoids) in the 50 metre to 20 kilometre range.”

Vulcanoid search diagram
The modern day Vulcanoid search strategy. (Diagram courtesy of Landon Curt Noll, used with permission).

Mr. Noll plans to resume his hunt during the August 21st, 2017 total solar eclipse spanning the continental United States. Totality for this eclipse will have a maximum duration of 2 minutes and 40 seconds. Circumstances during the next solar eclipse (a hybrid annular-total crossing central Africa on November 3rd, 2013) will be much more difficult, with a max totality located out to sea of only 1 minute and 40 seconds.

Libyan 2
Mr. Noll talks with a local reporter during the 2006 total solar eclipse expedition to Libya. (Photograph courtesy of Landon Curt Noll, used with permission).

Still, we think it’s amazing that the quest for Vulcan (or at least Vulcanoids) is alive and well and being spearheaded by adventurous and innovative amateur astronomers. In the words of Vulcan’s native fictional son, may it “Live Long & Prosper!”

–          Read more about Edison vs. the Chickens & the eclipse of 1878 here.

–          For a fascinating read on the subject, check out In Search for planet Vulcan.

–          Read more of Mr. Noll’s fascinating search for Vulcanoids here.

Opportunity rover Days Away from Mars Mountain Quest

Opportunity rover’s view from very near the foothills of Solander Point looking along the rim and vast expanse of Endeavour Crater. Solander Point is the 1st Martian Mountain NASA’s Opportunity will climb and the rovers next destination. Solander Point may harbor clay minerals indicative of a past Martian habitable environment. This navcam mosaic was assembled from raw images taken on Sol 3374 (July 21, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com) See complete panoramic mosaic below

Opportunity rover’s view from very near the foothills of Solander Point looking along the rim and vast expanse of Endeavour Crater. This area exhibits gypsum signatures and numerous blocks of intriguing rock. Solander Point is the 1st Martian Mountain NASA’s Opportunity will climb and the rovers next destination. Solander Point may harbor clay minerals indicative of a past Martian habitable environment. This navcam mosaic was assembled from raw images taken on Sol 3374 (July 21, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com).
See complete panoramic mosaic below. Story updated with further details[/caption]

Exactly a decade after blasting off for the Red Planet and discovering a wide swath of water altered rocks and minerals in the ensuing years by exploring countless craters large and small, NASA’s intrepid Opportunity rover is just days away from arriving at her next big quest – a Martian mountain named Solander Point that may possess the key chemical ingredients necessary to sustain Martian life forms.

“We are parked 200 meters away from the bench at Solander Point,” Ray Arvidson told Universe Today exclusively. Arvidson is the mission’s deputy principal scientific investigator from Washington University in St. Louis, Mo. Furthermore, this area exhibits signatures related to water flow.

Solander Point also represents ‘something completely different’ – the first mountain the intrepid robot will ever climb.

“This will be Opportunity’s first mountain and the view from the ridge crest should be spectacular,” wrote Larry Crumpler, a science team member from the New Mexico Museum of Natural History & Science, in his latest field report about the 10 years ongoing Mars Exploration Rover (MER) mission.

Indeed the rover is now just a few short drives southward from making landfall on the northern tip of the point in her current trek across the relatively flat plains around the rim of Endeavour crater.

“We are now only about 180 meters from the new mountain, Solander Point.”

Opportunity rover location in the latest MRO/HiRISE color image. The green line shows more or less the route we hope to take to the base of Solander point. Since it is only a couple of hundred meters away, we could be there is a couple of drives. Maybe by the end of next week. The label say "3374" but this is also roughly the location through 3379.
Opportunity rover location in the latest MRO/HiRISE color image. The green line shows more or less the route we hope to take to the base of Solander point. Since it is only a couple of hundred meters away, the rover could be there is a couple of drives. Maybe by the end of next week. The label say “3374” but this is also roughly the location through 3379. NASA/JPL/Larry Crumpler

But before moving onward, Arvidson explained that the rover will briefly pause here “at dark terrain” for some exciting science due to water related spectral observations from the CRISM instrument captured by NASA’s Mars Reconnaissance Orbiter (MRO) circling overhead.

“CRISM data [from Mars orbit] shows a relatively deep 1.9 micrometer absorption feature due to H2O-bearing minerals,” said Arvidson.

This past spring, Opportunity made the historic discovery of clay minerals and a habitable environment on a low hill called Cape York at the rover’s prior stop along the rim of Endeavour crater.

Solander was selected as the robot’s next destination because it simultaneously offers a goldmine of science as well as north facing slopes – where Opportunity’s solar wings can more effectively soak up the sun’s rays to generate life giving electrical power during the next Martian winter.

But since Opportunity is currently generating plenty of power from her solar arrays and arriving with a bonus cushion of time before the looming onset of her 6th Martian winter, the team decided to take a small detour to the southeast and spend several sols (or Martian days) exploring an area of intriguing geology of outcrops, gypsum signatures and more on the bench surrounding the base of the mountain.

“We slowed down this week so that we could check out the rocks here where there is a strange hydration signature from orbital remote sensing,” says Crumpler.

“This is also an area that appears to have more large blocks in the HiRISE images [from Mars orbit], so we are checking out one of the blocks, “Black Shoulder”.

“We are hoping that the rocks on the ridge crest will be spectacular too,” notes Crumpler.

Opportunity rover’s view very near the foothills of Solander Point along the rim and vast expanse of Endeavour Crater.  Solander Point is the 1st Martian Mountain NASA’s Opportunity will climb and the rovers next destination. Solander Point may harbor clay minerals indicative of a past Martian habitable environment. This navcam panoramic mosaic was assembled from raw images taken on Sol 3374 (July 21, 2013).  Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com)
Opportunity rover’s view very near the foothills of Solander Point along the rim and vast expanse of Endeavour Crater. This area exhibits gypsum signatures and numerous blocks of intriguing rock. Solander Point is the 1st Martian Mountain NASA’s Opportunity will climb and the rovers next destination. Solander Point may harbor clay minerals indicative of a past Martian habitable environment. This navcam panoramic mosaic was assembled from raw images taken on Sol 3374 (July 21, 2013). Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com)

Opportunity is using the science instruments on her 3 foot ( 1 meter) long robotic arm to conduct brief in-situ investigations of “Black Shoulder” with the Microscopic Imager (MI) and the Alpha Particle X-ray Spectrometer (APXS).

And …. it’s ‘Mountains Galore’ from here on out for the remainder of Opportunity’s Magnificent Mission to Mars.

Why? Because Opportunity is nearing the foothills of a long chain of eroded segments of the crater wall of Endeavour crater which spans a humongous 14 miles (22 kilometers) wide.

Solander Point may harbor deposits of phyllosilicate clay minerals – which form in neutral pH water – in a thick layer of rock stacks indicative of a past Martian habitable zone.

The rover team is discussing the best way to approach and drive up Solander.

“One idea is to drive part way up Solander from the west side of the rim, turn left and then drive down the steeper north facing slopes with the stratographic sections,” Ray Arvidson explained to Universe Today.

“That way we don’t have to drive up the relatively steeper slopes.”

“The rover can drive up rocky surfaces inclined about 12 to 15 degrees.”

“We want to go through the stratographic sections on the north facing sections,” Arvidson told me.

Opportunity rover moves closer to the foothills of Solander Point along the rim and vast expanse of Endeavour Crater.  The rover investigated one of the large rocks here with her microscopic imager and X-Ray spectrometer. Soon she will start climbing up Solander -  her 1st Martian Mountain ascent.  This navcam panoramic mosaic was assembled from raw images taken on Sol 3376 (July 23, 2013).  Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com)
Opportunity rover moves closer to the foothills of Solander Point along the rim and vast expanse of Endeavour Crater. The rover investigated one of the large rocks near here with her microscopic imager and X-Ray spectrometer. Soon she will start climbing up Solander – her 1st Martian Mountain ascent. This navcam panoramic mosaic was assembled from raw images taken on Sol 3376 (July 23, 2013).
Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer (kenkremer.com)

Today (July 28) is Sol 3380 for a mission that was only warrantied to last 90 Sols!

Opportunity’s total driving distance exceeds 23.6 miles (37.9 kilometers). She has snapped over 182,000 images.

The "work volume". This view from the front hazcams shows the rock target that is being checked out before the final slog to the south. With luck, by the end of next week we will be plinking around the base of yonder mountain. "Plinking" is a geological term for wandering around with your hammer trying to get a handle on the local outcrops before plunging ahead with mapping and asking the rocks serious questions.  Credit: NASA/JPL/Larry Crumpler
The “work volume”. This view from the front hazcams shows the rock target that is being checked out before the final slog to the south. With luck, by the end of next week we will be plinking around the base of yonder mountain. “Plinking” is a geological term for wandering around with your hammer trying to get a handle on the local outcrops before plunging ahead with mapping and asking the rocks serious questions. Credit: NASA/JPL/Larry Crumpler

Meanwhile on the opposite side of Mars at Gale Crater, Opportunity’s younger sister rover Curiosity also discovered a habitable environment originating from a time when the Red Planet was far warmer and wetter billions of years ago.

And like Opportunity, Curiosity is also trekking towards a mountain rich in sedimentary layers hoping to unveil the mysteries of Mars past. But Curiosity likely won’t arrive at 3.4 mile (5.5 km) high Mount Sharp for another year.

Ken Kremer

Traverse Map for NASA’s Opportunity rover from 2004 to 2013.  This map shows the entire path the rover has driven during more than 9 years and over 3374 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location near foothills of Solander Point at the western rim of Endeavour Crater.  Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer
Traverse Map for NASA’s Opportunity rover from 2004 to 2013
This map shows the entire path the rover has driven during more than 9 years and over 3374 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location near foothills of Solander Point at the western rim of Endeavour Crater. Opportunity discovered clay minerals at Esperance – indicative of a habitable zone. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer

…………….
Learn more about Mars, Curiosity, Opportunity, LADEE, MAVEN, Antares and more at Ken’s upcoming lecture presentations

Aug 12: “RockSat-X Suborbital Launch, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM

Third Bright Supernova Discovered In Spiral Galaxy M74

One of the first photos of the possible new supernova in the nearby galaxy M74 taken by the Italian Supernova Search Project. The object is located 93" east and 135" south of the galaxy's center. Click to learn more about the search group. Credit: Fabio Martinelli

I love this galaxy. Not only does M74 display a near perfect spiral form but if this latest supernova is the third to “go boom” in the galaxy in just 11 years. The new object, designated PSN J01364816+1545310, was discovered blazing near 12.4 magnitude by the Lick Observatory Supernova Search at Lick Observatory near San Jose, Calif. “PSN” stands for “possible supernova” and the long string of numbers give the object’s position in the sky using the celestial equivalents of latitude and longitude.

Update: The supernova has now been confirmed, and is now officially named SN 2013ej.

Supernova 2013ej, taken remotely on July 29, 2013 from iTelescope Network using the Siding Spring Observatory. Credit: Ernesto Guido and Nick Howes.
Supernova 2013ej, taken remotely on July 29, 2013 from iTelescope Network using the Siding Spring Observatory. Credit: Ernesto Guido and Nick Howes/Remanzacco Observatory.

Additional information and imagery of this from the Remanzacco Observatory team can be found at their website, including an animation of a “before and after” the supernova exploded.

M74 is a classic spiral galaxy with arms that appear to unwind from a bright, star-packed nucleus. Located 32 million light years away in the constellation Pisces, M74 contains about 100 billion stars. The spiral arms are dotted with dense star clusters and pink clouds of fluorescing hydrogen gas. Credit: Jim Misti
M74 is a classic spiral galaxy with arms that appear to unwind from a bright, star-packed nucleus. Located 32 million light years away in the constellation Pisces, M74 contains about 100 billion stars. The spiral arms are dotted with dense star clusters and pink clouds of fluorescing hydrogen gas. Credit: Jim Misti

The Lick search uses a fully robotic or automated 30-inch (76 cm) telescope dedicated to scanning the skies for new supernovae. It nailed M74’s latest exploding star on July 25. Two previous supernovae flared in the galaxy – SN 2002ap and SN 2003gd – and rose to 12th and 13th magnitude respectively before fading away into obscurity.

Size comparison of our Milky Way spiral galaxy with M74. The Milky Way measures about 100,000 light years across; M74 about 30,000. Credit: NASA (left) and Jim Misti
Size comparison of our Milky Way spiral galaxy with M74. The Milky Way measures about 100,000 light years across; M74 about 30,000. Credit: NASA (left) and Jim Misti

Three’s the charm as they say. A team of astronomers using a spectrograph at the Faulkes Telescope South at Siding Spring, Australia teased apart the supernova’s light and now know exactly what blew up. It appears our newcomer was originally a supergiant star at least 8 times as massive as the sun. After a relatively brief lifetime measured in the millions of years, the supergiant gobbled up the last of its fuel. With the gas gauge on “empty” and no new energy being produced in the core to hold back  the force of gravity, the star imploded, sending a shockwave rocketing back in the opposite direction that tore it to bits.

When a massive star runs out of nuclear fuel in its core, the energy that has prevented the force of gravity from crushing the star is gone. Gravity now finally wins and collapses the star which then rebounds in a huge explosion. Credit: ESO
When a massive star runs out of nuclear fuel in its core, the energy that has prevented the force of gravity from crushing it is gone. Gravity finally gains the upper hand causing the star to implode. A rebounding shock wave blows it to bits. Sometime a city-sized, dense stellar remnant called a neutron star remains after the blast. Credit: ESO

Called a Type II supernova explosion, the blast hurtles star stuff into space at up to 45,000 miles per second (70,000 km/sec). More amazing, a powerful supernova explosion can release as much energy as the sun during its entire 10 billion year lifetime. No wonder even small telescopes can spot these cataclysmic events from millions of light years away!

The galaxy M74, the 74th entry in 18th century astronomer Charles Messier's catalog, is found about 1.5 degrees east-northeast of the star Eta Piscium just to the right of the small constellation Aries the Ram. The map shows the sky around 1 a.m. tomorrow morning facing east.  Stellarium
The galaxy M74, the 74th entry in 18th century astronomer Charles Messier’s catalog, is found about 1.5 degrees east-northeast of the star Eta Piscium just to the right of the small constellation Aries the Ram. The map shows the sky around 1 a.m. tomorrow morning facing east. Stellarium

As additional photos and measurements come in,  amateur astronomers with 8-inch and larger telescopes will have no problem spying the supernova once the last quarter moon departs the vicinity. It’s located 93″ (1.5′)  east and 135″ (more than 2′) southeast of the galaxy’s core. The map and photo will help you track it down.

This map measures only about 1/2-degree wide and shows the galaxy up close with the supernova marked SN. Selected star magnitudes from the AAVSO are shown to help you navigate to the object as well as estimate its brightness. North is up, west to the right. Map created with Chris Marriott's SkyMap software
This map measures only about 1/2-degree wide and shows the galaxy up close with the supernova marked SN. Selected star magnitudes from the AAVSO are shown to help you navigate to the object as well as estimate its brightness. North is up, west to the right. Map created with Chris Marriott’s SkyMap software

While M74 is relatively bright and appears spectacular in long-exposure photos, it looks like a large, dim featureless glow in smaller telescopes. Be patient and take your time to “star hop” to the supernova using the more detailed map. Matter of fact, you may want to wait until Tuesday morning or later to look. That’s when the waning moon will finally depart the area. Let’s hope our new guest remains bright.

Good luck meeting the latest star to mark the end of its life with the biggest blowout of all. For more information and photos, stop by Dave Bishop’s Latest Supernovae site.

* This article was updated at 6:30 pm CDT on 7/28/13