JPL’s Blaine Baggett and former JPL director Ed Stone talk The Stuff of Dreams, a documentary about an era in planetary exploration that was both exhilarating and exasperating. Emily Lakdawalla explains why Curiosity has joined the fraternity of backward driving rovers on Mars, and Bill Nye considers the not-too-distant future when airliners and spaceliners will share the sky…
Behold the first geological map of Ganymede, Jupiter’s largest moon
by Lauren Davis
Four hundred years ago, Galileo Galilei observed Ganymede in orbit around Jupiter. This week, a team of planetary scientists unveiled the first global geological map of our solar system’s largest moon.
Using images obtained by NASA’s Voyager 1 and 2 spacecraft and the Galileo orbiter, a team led by Geoffrey Collins of Wheaton College pieced together a mosaic image of the planet, giving us our first complete image of the geological features of the satellite. Above, you can see the moon centered at 200 west longitude. The darker areas represent the very old and heavily cratered region of Ganymede, while the lighter areas are somewhat younger regions marked with grooves and ridges…
What Astronomers Are Still Discovering About the Big Bang Theory
A half-century after it was confirmed, the theory still yields new secrets
by Claudia Dreifus
On a bright spring morning 50 years ago, two young astronomers at Bell Laboratories were tuning a 20-foot, horn-shaped antenna pointed toward the sky over New Jersey. Their goal was to measure the Milky Way galaxy, home to planet Earth.
To their puzzlement, Robert W. Wilson and Arno A. Penzias heard the insistent hiss of radio signals coming from every direction—and from beyond the Milky Way. It took a full year of testing, experimenting and calculating for them and another group of researchers at Princeton to explain the phenomenon: It was cosmic microwave background radiation, a residue of the primordial explosion of energy and matter that suddenly gave rise to the universe some 13.8 billion years ago. The scientists had found evidence that would confirm the Big Bang theory, first proposed by Georges Lemaître in 1931.
“Until then, some cosmologists believed that the universe was in a steady state without a singular beginning,” says Wilson, now 78 and a senior scientist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. “The finding helped rule that out.”…
This runaway pulsar has produced the longest jet trail ever detected
by George Dvorsky
See that purple stream at the bottom right? It’s the helical jet from a runaway pulsar that’s streaking across the Milky Way at speeds reaching five million mph. But more extraordinary than that is how freakishly long this thing is.
A pulsar is a type of rapidly spinning neutron star, which is the small and incredibly dense remnant of a much more massive star. Pulsars are known to produce long X-ray jets of high-energy particles — but this one’s the longest ever seen.
The pulsar is called IGR J11014-6103 and it was imaged by NASA’s Chandra X-ray Observatory. It’s located about 60 light-years from the center of the supernova that created it, SNR MSH 11-61A. It’s one of the fastest pulsars ever observed. NASA estimates its speed as being somewhere between 2.5 million and 5 million mph (about 1000 km/s)…
You know when you’re having a bad day when you get hit by a billion-ton asteroid. But for a pulsar 37,000 light-years away, it’s just a another day at the office. And besides, PSR J0738-4042 has an uber-powerful X-ray blaster to deal with errant space rocks…
Lunar distance is a measurement of the distance from the Earth to the Moon. This diagram shows the distance, averaging 384,400 km (238,900 mi), to scale, as well as the Earth and the Moon (scroll to see the entire image).
Line below Earth represents distance of Earth’s centre from the system barycentre. Line below the Moon represents perigee and apogee with the moon at the semi‐major axis position. Moon shown with correct side facing earth, but without any pretty shading.
The below information refers to the original version of this file, which was twice the size of the current version (i.e. it’s now 14.25 km/px). Sorry but Photoshop wasn’t saving them very well, so I had to switch to GraphicConverter, which is limited to 16,000 pixels across.
Earth-Moon system at a scale of 7.1224 km/px (0.140402 px/km)
Earth polar diameter = 12,713.5 km (893px) ⇒ 7.1224 km/px
Moon equatorial diameter = 3,476.2 km (244px)
Lunar apogee = 405696 km (28480px)
Lunar semi‐major axis = 384400 km (26985px)
Lunar perigee = 363104 km (25490px)
System barycenter = 4700 km (330px)
Scale chosen because Photoshop only supports images 30,000 pixel in width, and scaling the Earth by 50% just about fits with this, all other measurements derived from there.
For most of its lifetime, Voyager 1 has been traveling through uncharted territory. Initially launched to study the outer planets, Voyager 1 has soldiered on past Jupiter and Saturn and on to the outer edges of the solar system.
It’s currently the farthest human-made object from Earth, but when will it be the first spacecraft to travel between the stars? Well, we won’t know until we answer two more fundamental questions: Where does our solar system end and the rest of the space between the stars begin? And if you were at the “edge” of our solar system, how would you know you had left?
Recent scientific discussions on the Voyager spacecraft missions have captivated many people. And as the scientific debate swirled around the internet in near-real time, it became clear that these questions are not easy to answer…
The beautiful leftover debris from an exploded star
This image of the debris of an exploded star - known as supernova remnant 1E 0102.2-7219, or “E0102” for short - features data from NASA’s Chandra X-ray Observatory. E0102 is located about 190,000 light years away in the Small Magellanic Cloud, one of the nearest galaxies to the Milky Way. It was created when a star that was much more massive than the Sun exploded, an event that would have been visible from the Southern Hemisphere of the Earth over 1000 years ago.
Chandra first observed E0102 shortly after its launch in 1999. New X-ray data have now been used to create this spectacular image and help celebrate the ten-year anniversary of Chandra’s launch on July 23, 1999. In this latest image of E0102, the lowest-energy X-rays are colored orange, the intermediate range of X-rays is cyan, and the highest-energy X-rays Chandra detected are blue. An optical image from the Hubble Space Telescope (in red, green and blue) shows additional structure in the remnant and also reveals foreground stars in the field…
The Cosmos, Explained: Neil deGrasse Tyson On His New Series
by Douglas Main
When astronomer Carl Sagan hosted the 13-part TV Series “Cosmos: A Personal Journey,” in 1980, it soon become most widely watched PBS show in the world, and still holds a legendary place in the hearts of many. Now, more than three decades later, the series is being brought back, with astrophysicist Neil deGrasse Tyson as cosmic guide. Tyson, who also spoke with Popular Science for our March issue, chatted with us about the show…
When Galileo Galilei shook up the scientific community with evidence of a heliocentric world, he had a little tube fitted with two pieces of glass to thank. But just how this gadget evolved in the nascent days of astronomy is poorly known.
That uncertainty has inspired a group of researchers to compile the most extensive database of early refracting telescopes to date, presented here yesterday during a poster session at the annual meeting of AAAS, which publishes Science. Now, the scientists plan to use modern optics to recreate what Galileo—and the naysaying observers of his time—experienced when they first peered through these tubes at the rings of Saturn, the moons of Jupiter, and the phases of Venus…
One of our closest galactic neighbors shows its awesome beauty in this image from NASA’s Spitzer Space Telescope. M33, also known as the Triangulum Galaxy, is a member of what’s known as our Local Group of galaxies. Along with our own Milky Way, this group travels together in the universe, as they are gravitationally bound. In fact, M33 is one of the few galaxies that is moving toward the Milky Way despite the fact that space itself is expanding, causing most galaxies in the universe to grow farther and farther apart.
When viewed with Spitzer’s infrared eyes, this elegant spiral galaxy sparkles with color and detail. Stars appear as glistening blue gems (several of which are actually foreground stars in our own galaxy), while dust rich in organic molecules glows green. The diffuse orange-red glowing areas indicate star-forming regions, while small red flecks outside the spiral disk of M33 are most likely distant background galaxies. But not only is this new image beautiful, it also shows M33 to be surprising large – bigger than its visible-light appearance would suggest…
A look at today’s Sun in this three-wavelength image (094, 335 and 193 angstroms). Each highlights a different part of the corona. The bright area to the right is Active Region 1974, which has been crackling with M-class solar flares the past few hours.
Gargantuan jet blasts away from supermassive black hole
Just weeks after NASA’s Chandra X-ray Observatory began operations in 1999, the telescope pointed at Centaurus A (Cen A, for short). This galaxy, at a distance of about 12 million light years from Earth, contains a gargantuan jet blasting away from a central supermassive black hole.
Since then, Chandra has returned its attention to this galaxy, each time gathering more data. And, like an old family photo that has been digitally restored, new processing techniques are providing astronomers with a new look at this old galactic friend.
This new image of Cen A contains data from observations, equivalent to over nine and a half days worth of time, taken between 1999 and 2012. In this image, the lowest-energy X-rays Chandra detects are in red, while the medium-energy X-rays are green, and the highest-energy ones are blue…
Arp 273 is a group of interacting galaxies, lying 300 million light years away in the constellation Andromeda and first discovered in 1966. In this photograph from the Hubble Space Telescope, the larger of the spiral galaxies, known as UGC 1810, has a disk that is tidally distorted into a rose-like shape by the gravitational tidal pull of the companion galaxy below it, known as UGC 1813. A swath of blue jewels across the top is the combined light from clusters of intensely bright and hot young blue stars.
Alex Filippenko: “Dark Energy and the Runaway Universe”
We expected the attractive force of gravity to slow down the rate at which the Universe is expanding. But observations of very distant exploding stars (supernovae) show that the expansion rate is actually speeding up, a remarkable discovery that was honored with the 2011 Nobel Prize in
Physics to the teams’ leaders. Over the largest distances, the Universe seems to be dominated by a repulsive “dark energy” — an idea Albert Einstein had suggested in 1917 but renounced in 1929 as his “biggest blunder.” It stretches space itself faster and faster with time. But the physical origin and nature of dark energy, which makes up about 70% of the contents of the Universe, is probably the most important unsolved problem in all of physics; it may provide clues to a unified quantum theory of gravity.
About the Speaker: Alex Filippenko is the Richard & Rhoda Goldman Distinguished Professor in the Physical Sciences. His accomplishments, documented in about 700 research papers, have been recognized by several major prizes, and he is one of the world’s most highly cited astronomers. In 2009 he was elected to the National Academy of Sciences, and he shared part of the Gruber Cosmology Prize in 2007. He has won the top teaching awards at UC Berkeley and has been voted the “Best Professor” on campus a record 9 times.
In 2006 he was selected as the Carnegie/CASE National Professor of the Year among doctoral institutions, and in 2010 he won the ASP’s Emmons Award for undergraduate teaching. He has produced five astronomy video courses with “The Great Courses,” coauthored an award-winning textbook, and appears in numerous TV documentaries including about 40 episodes of “The Universe” series. An avid tennis player, hiker, and skier, he enjoys world travel and is addicted to observing total solar eclipses (11 so far).