Hubble Archives

August 6, 2015December 23, 2015 by David Dickinson

Stealing Sedna

An artist's conception of Sedna. this assumes that Sedna has a tiny as yet undiscovered moon. Image credit; NASA/JPl-Caltech

Turns out, our seemly placid star had a criminal youth of cosmic proportions.

A recent study out from Leiden Observatory and Cornell University may shed light on the curious case of one of the solar system’s more exotic objects: 90377 Sedna.

Distant Sedna (circled) moving against the starry background). Image credit: NASA/Hubble

A team led by astronomer Mike Brown discovered 90377 Sedna in late 2003. Provisionally named 2003 VB12, the object later received the name Sedna from the International Astronomical Union, after the Inuit goddess of the sea.

From the start, Sedna was an odd-ball. Its 11,400 year orbit takes it from a perihelion of 76 astronomical units (for context, Neptune is an average of 30 AUs from the Sun) to an amazing 936 AUs from the Sun. (A thousand AUs is 1.6% of a light year, and 0.4% of the way to Proxima Centauri, the closest star to our solar system). Currently at a distance of 86 AU and headed towards perihelion in 2076, we’re lucky we caught Sedna as it ‘neared’ (we use the term ‘near’ loosely in this case!) the Sun.

But this strange path makes you wonder what else is out there, and how Sedna wound up in such an eccentric orbit.

Zooming out; the inner solar system (upper left), the outer solar system (upper right), the orbit of Sedna (lower right) and the inner edge of the Oort cloud (lower left). Image credit: NASA

The study, entitled How Sedna and family were captured in a close encounter with a solar sibling looks at the possibility that Sedna may have been snatched from another star early on in our Sun’s career (of interstellar crime, perhaps?) The team used supercomputer simulations modeling 10,000 encounters to discover which types of near stellar passages might result in an ice dwarf world in a Sedna-like orbit.

“We constrained the parent star of Sedna to have between one and two times the mass of the Sun and its closest approach to be 200-400 AUs,” Dr. Lucie Jilkova of Leiden Observatory told Universe Today. “Such a close encounter probably happened while the Sun was still a member of its birth star cluster — a family of about 1,000 stars, so called solar siblings, born at the same time relatively close together — which was about 4 billion years ago.”

The orbit of Sedna. (Note Neptune and Pluto towards the center) Image credit: NASA/JPL

The best fit for what we see today in the outer solar system in the case of Sedna, is a close (340 AU) passage from the Sun — that’s over 11 times Neptune’s distance — of a 1.8 solar mass star inclined at an angle of 17-34 degrees to the ecliptic. Sedna’s current orbital inclination is 12 degrees.

Rise of the Sednitos

The paper assigns the term ‘Sednitos’ (also sometimes referred to as ‘Sednoids’) for these Edgeworth-Kuiper Belt intruders with similar characteristics to Sedna. In 2012, 2012 VP113, dubbed the ‘twin of Sedna,’ was discovered by astronomers at the Cerro Tololo Inter-American Observatory in a similar looping orbit. The ‘VP’ designation earned the as yet unnamed remote world the brief nickname ‘Biden’ after U.S. Vice President Joe Biden… hey, it was an election year.

There’s good reason to believe something(s?) out there shepherding these Senitos into a similar orbit with a comparable argument of perihelion. Researchers have suggested the existence of one or several planetary mass objects loitering out in the 200-250 AU range of the outer solar system… note that this is

a separate scientific-based discussion versus any would-be Nibiru related non-sense, don’t even get

us started…

If researchers in the study are correct, Sedna may have lots of company, with perhaps 930 planetesimals predicted in the ‘Sednito region’ of the solar system from 50 to 1,000 AUs and 430 more additional planetesimals littering the inner Oort cloud from the same early event.

“We focused on a particular example of a stellar encounter with characteristics from the ranges mentioned,” Dr. Jilkova said. “For this example, we estimated that there would be about 430 bodies similar to Sedna in the outer solar system (beyond 75 AU).”

Fun fact: One possible controversial candidate for the birth cluster of Sol and our solar system is the open cluster M67 in Cancer. It’s an intriguing notion to try and track down the star we stole Sedna from 4 billion years ago using spectral analysis, though researchers in the study point out that the other more massive star is probably an aging white dwarf by now.

Astronomy from the surface of Sedna is mind-bending to contemplate. Currently 86 AU from the Sun and headed towards perihelion in 2076, Sol would appear only 20” across from the surface of Sedna, but would still shine at magnitude -17 to -18 near perihelion, about 40 to 100 times brighter than a Full Moon. Fast forward about 5,500 years towards aphelion, however, and the Sun would dim to a paltry magnitude -12, a full magnitude (2.5 times) dimmer than the Full Moon.

The view from Sedna looking towards the inner solar system in 2015. Image credit: Starry Night Education Software. — The view from Sedna looking towards the inner solar system in 2015. Note the five degree red field of view marker. Image credit: Starry Night Education Software.

Shining at magnitude +21 in the constellation Taurus, astronomers know little else about Sedna. Based on brightness estimates, Sedna measures about 1,000 km in diameter. It does appear to be the reddest object in the solar system, and may turn out to be the ‘red twin of Pluto’ as recently revealed by NASA’s New Horizons spacecraft, complete with a surface rich in tholins.

And a new generation of observatories may uncover a treasure trove of Sednitos. The European Space Agency’s Gaia astrometry mission should uncover lots of new asteroids, comets, exoplanets and distant Kuiper Belt objects as a spin-off to its primary mission. Then there’s the Large Synoptic Survey Telescope, set to see first light in 2019.

“The key piece of the puzzle is to actually observe more Sedna-like objects.” Dr Jilkova said. “Currently, we know only of two such bodies. More discoveries are expected in the following years and they will shed light on the origin of Sedna and its family and the ‘criminal record’ of the Sun.”

It’s a fascinating story of interstellar whodunit for sure, as our Sun’s early days of wanton juvenile delinquency unravel before the eyes of modern day astronomical detectives.

June 15, 2015December 23, 2015 by Nancy Atkinson

Distant Stellar Nurseries: This Time, in High Definition

The Milky Way glitters above the ALMA array in this image taken from a time lapse sequence during the ESO Ultra HD Expedition.

This article is a guest post by Anna Ho, who is currently doing research on stars in the Milky Way through a one-year Fulbright Scholarship at the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany.

In the Milky Way, an average of seven new stars are born every year. In the distant galaxy GN20, an astonishing average of 1,850 new stars are born every year. “How,” you might ask, indignant on behalf of our galactic home, “does GN20 manage 1,850 new stars in the time it takes the Milky Way to pull off one?”

To answer this, we would ideally take a detailed look at the stellar nurseries in GN20, and a detailed look at the stellar nurseries in the Milky Way, and see what makes the former so much more productive than the latter.

But GN20 is simply too far away for a detailed look.

This galaxy is so distant that its light took twelve billion years to reach our telescopes. For reference, Earth itself is only 4.5 billion years old and the universe itself is thought to be about 14 billion years old. Since light takes time to travel, looking out across space means looking back across time, so GN20 is not only a distant, but also a very ancient, galaxy. And, until recently, astronomers’ vision of these distant, ancient galaxies has been blurry.

Consider what happens when you try to load a video with a slow Internet connection, or when you download a low-resolution picture and then stretch it. The image is pixelated. What was once a person’s face becomes a few squares: a couple of brown squares for hair, a couple of pink squares for the face. The low-definition picture makes it impossible to see details: the eyes, the nose, the facial expression.

A face has many details and a galaxy has many varied stellar nurseries. But poor resolution, a result simply of the fact that ancient galaxies like GN20 are separated from our telescopes by vast cosmic distances, has forced astronomers to blur together all of this rich information into a single point.

The situation is completely different here at home in the Milky Way. Astronomers have been able to peer deep into stellar nurseries and witness stellar birth in stunning detail. In 2006, the Hubble Space Telescope took this unprecedentedly detailed action shot of stellar birth at the heart of the Orion Nebula, one of the Milky Way’s most famous stellar nurseries:

hs-2006-01-a-xlarge_web — A detailed close-up of stellar birth. Credit: NASA,ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team

There are over 3,000 stars in this image: The glowing dots are newborn stars that have recently emerged from their cocoons. Stellar cocoons are made of gas: thousands of these gas cocoons sit nestled in immense cosmic nurseries, which are rich with gas and dust. The central region of that Hubble image, encased by what looks like a bubble, is so clear and bright because the massive stars within have blown away the dust and gas they were forged from. Majestic stellar nurseries are scattered all over the Milky Way, and astronomers have been very successful at uncloaking them in order to understand how stars are made.

Observing nurseries both here at home and in relatively nearby galaxies has enabled astronomers to make great leaps in understanding stellar birth in general: and, in particular, what makes one nursery, or one star formation region, “better” at building stars than another. The answer seems to be: how much gas there is in a particular region. More gas, faster rate of star birth. This relationship between the density of gas and the rate of stellar birth is called the Kennicutt-Schmidt Law. In 1959, the Dutch astronomer Maarten Schmidt raised the question of how exactly increasing gas density influences star birth, and forty years later, in an illustration of how scientific dialogues can span decades, his American colleague Robert Kennicutt used data from 97 galaxies to answer him.

Understanding the Kennicutt-Schmidt Law is crucial for determining how stars form and even how galaxies evolve. One fundamental question is whether there is one rule that governs all galaxies, or whether one rule governs our galactic neighborhood, but a different rule governs distant galaxies. In particular, a family of distant galaxies known as “starburst galaxies” seems to contain particularly productive nurseries. Dissecting these distant, highly efficient stellar factories would mean probing galaxies as they used to be, back near the beginning of the universe.

Enter GN20. GN20 is one of the brightest, most productive of these starburst galaxies. Previously a pixelated dot in astronomers’ images, GN20 has become an example of a transformation in technological capability.

In December 2014, an international team of astronomers led by Dr. Jacqueline Hodge of the National Radio Astronomy Observatory in the USA, and comprising astronomers from Germany, the United Kingdom, France, and Austria, were able to construct an unprecedentedly detailed picture of the stellar nurseries in GN20. Their results were published earlier this year.

The key is a technique called interferometry: observing one object with many telescopes, and combining the information from all the telescopes to construct one detailed image. Dr. Hodge’s team used some of the most sophisticated interferometers in the world: the Karl G. Jansky Very Large Array (VLA) in the New Mexico desert, and the Plateau de Bure Interferometer (PdBI) at 2550 meters (8370 feet) above sea level in the French Alps.

With data from these interferometers as well as the Hubble Space Telescope, they turned what used to be one dot into the following composite image:

hodgeetal-1412-2132_f7 — GN20 in unprecedented detail (false color image). The 10 kpc (10,000 parsec) scale corresponds to 32,600 light-years. Image credit: Jacqueline Hodge et al. 2015

This is a false color image, and each color stands for a different component of the galaxy. Blue is ultraviolet light, captured by the Hubble Space Telescope. Green is cold molecular gas, imaged by the VLA. And red is warm dust, heated by the star formation it is shrouding, detected by the PdBI.

Unbundling one pixel into many enabled the team to determine that the nurseries in a starburst galaxy like GN20 are fundamentally different from those in a “normal” galaxy like the Milky Way. Given the same amount of gas, GN20 can churn out orders of magnitude more stars than the Milky Way can. It doesn’t simply have more raw material: it is more efficient at fashioning stars out of it.

ann12099a — Some of the 66 radio antennas of ALMA, which can be linked to act like a much larger telescope. Image credit: ALMA (ESO/NAOJ/NRAO)/B. Tafreshi (twanight.org)

This kind of study is currently unique to the extreme case of GN20. However, it will be more common with the new generation of interferometers, such as the Atacama Large Millimeter/submillimeter Array (ALMA).

Located 5000 meters (16000 feet) high up in the Chilean Andes, ALMA is poised to transform astronomers’ understanding of stellar birth. State-of-the-art telescopes are enabling astronomers to do the kind of detailed science with distant galaxies – ancient galaxies from the early universe – that was once thought to be possible only for our local neighborhood. This is crucial in the scientific quest for universal physical laws, as astronomers are able to test their theories beyond our neighborhood, out across space and back through time.

May 28, 2015December 23, 2015 by Jason Major

Hubble Captures a Collision in a Black Hole’s “Death Star” Beam

Activity within the jet from NGC 3852 imaged by Hubble. Credit: NASA, ESA, and E. Meyer (STScI).

Even the Empire’s planet-blasting battle station has nothing compared to the immense energy being fired from the heart of NGC 3862, a supermassive black hole-harboring elliptical galaxy located 300 million light-years away.

And while jets of high-energy plasma coming from active galactic nuclei have been imaged before, for the first time activity within a jet has been observed in optical wavelengths, revealing a quite “forceful” collision of ejected material at near light speeds.

Using archived image data acquired by Hubble in 1994, 1996, and 2002 combined with new high-resolution images acquired in 2014, Eileen Meyer at the Space Telescope Science Institute (STScI) in Baltimore, Maryland identified movement in visible clumps of plasma within the jet emitted from the nucleus of NGC 3862 (aka 3C 264). One of the outwardly-moving larger clumps could be seen gaining on a slower, smaller one in front of it and the two eventually collide, creating a shockwave that brightens the resulting merged mass dramatically.

Such a collision has never been witnessed before, and certainly not thousands of light-years out from the central supermassive black hole.

Close-up image of the jet as seen in 2014. Credit: NASA, ESA, and E. Meyer (STScI).

“Something like this has never been seen before in an extragalactic jet,” Meyer said. “This will allow us a very rare opportunity to see how the kinetic energy of the collision is dissipated into radiation.”

Jets like this are created when infalling material around an active (that is, “feeding”) supermassive black hole gets caught up in its powerful spinning and twisting magnetic fields. This accelerates the material even further and, rather than permitting it to descend down past the black hole’s event horizon, results in it getting shot out into space at velocities close to the speed of light.

When material approaches the black hole in even amounts the jets are fairly consistent. But if the inflow is uneven, the jets can consist of clumps or knots traveling outward at different speeds.

Because of the motion of the galaxy itself related to our own, the speed of the clumps can appear to actually move faster than the speed of light, especially when – as seen in NGC 3862 – a large clump has already paved the way within the jet. In reality the light speed limit has not been broken, but the apparent superluminal motion so far from the SMBH indicates that the material was ejected extremely energetically.

It’s expected that the combined clusters of material will continue to brighten over the next several decades.

You can see a video of the observations below, and watch a Google+ Hangout with Hubble team members about these observations here.

Source: Hubble news center

May 22, 2015December 23, 2015 by Bob King

Ceres Bright Spots Sharpen But Questions Remain

Latest image released by NASA of the spatter of white spots in the 57-mile-wide crater on the dwarf planet Ceres. Scientists with the Dawn mission believe they're highly reflective material, likely ice. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The latest views of Ceres’ enigmatic white spots are sharper and clearer, but it’s obvious that Dawn will have to descend much lower before we’ll see crucial details hidden in this overexposed splatter of white dots. Still, there are hints of interesting things going on here.

Comparison of the most recent photos of the white spots taken Dawn's current 4,500 miles vs. 8,400 miles on May 3. Credit: — Comparison of the most recent photos of the white spots taken Dawn’s current 4,500 miles vs. 8,400 miles on May 4. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The latest photo is part of a sequence of images shot for navigation purposes on May 16, when the spacecraft orbited 4,500 miles (7,200 km) over the dwarf planet. Of special interest are a series of troughs or cracks in Ceres crust that appear on either side of the crater housing the spots.

While the exact nature of the spots continues to baffle scientists, Christopher Russell, principal investigator for the Dawn mission, has narrowed the possibilities: “Dawn scientists can now conclude that the intense brightness of these spots is due to the reflection of sunlight by highly reflective material on the surface, possibly ice.”

Two views of an impact exposing water ice on Mars. The bright material conspicuous in this image was excavated from below the surface and deposited nearby by a 2008 impact that dug a crater about 8 meters (26 feet) in diameter. The extent of the bright patch was large enough for the Compact Reconnaissance Imaging Spectrometer for Mars, an instrument on NASA's Mars Reconnaissance Orbiter, to obtain information confirming the material to be water ice. Credit: NASA/JPL-Caltech/University of Arizona — The bright material in both photos was excavated from below the surface and deposited nearby by a 2008 impact that dug a crater about 26 feet (8 meters) in diameter. The extent of the bright patch was large enough for the Compact Reconnaissance Imaging Spectrometer for Mars, an instrument on NASA’s Mars Reconnaissance Orbiter, to obtain information confirming it as water ice. Credit: NASA/JPL-Caltech/University of Arizona

We’ve seen ice exposed by meteorite / asteroid impact before on Mars where recent impacts have exposed fresh ice below the surface long hidden by dust. In most cases the ice gradually sublimates away or covered by dust over time. But if Ceres’ white spots are ice, then we can reasonably assume they must be relatively new features otherwise they would have vaporized or sublimated into space like the Martian variety.

NASA's Hubble Space Telescope took these images of the asteroid 1 Ceres over a 2-hour and 20-minute span, the time it takes the Texas-sized object to complete one quarter of a rotation. — NASA’s Hubble Space Telescope took these images of the asteroid 1 Ceres over a 2-hour and 20-minute span, the time it takes the Texas-sized object to complete one quarter of a rotation. The observations were made in visible and in ultraviolet light. Hubble took the snapshots between December 2003 and January 2004. Credit: NASA, ESA, J. Parker, P. Thomas and L. McFadden

Much has been written – including here – that these spots are the same as those photographed in much lower resolution by the Hubble Space Telescope in 2004. But according the Phil Plait, who writes the Bad Astronomy blog, that’s false. He spoke to Joe Parker, who was part of the team that made the 2004 photos, and Parker says the Dawn spots and Hubble spots are not the same.

Could the spots have formed post-2004 or were they simply too small for Hubble to resolve them? That seems unlikely. The chances are slim we’d just happen to be there shortly after such a rare event occurred? And what happened to Hubble’s spot – did it sublimate away?

Video compiled from Dawn’s still frames of Ceres by Tom Ruen. Watch as the spots continue to reflect light even at local sunset.

Watching the still images of Ceres during rotation, it’s clear that sunlight still reflects from the spots when the crater fills with shadow at sunset and sunrise. This implies they’re elevated, and as far as I can tell from the sunrise photo (see below), the brightest spots appear to shine from along the the side of a hill or mountain. Could we be seeing relatively fresh ice or salts after recent landslides related to impact or tectonic forces exposed them to view?

The crater with white spots shortly after sunrise. The bright spots appear to be on a central mountain. It's unclear if the pair of spots below the bright pair are situated on a rise or the flat floor. Credit: NASA — Single from from the video shows the white spots shortly after sunrise. The brightest appear to be located on a central mountain peak. It’s unclear if the pair of spots below the bright pair are situated on a rise or the flat floor. Credit: NASA

Let’s visit another place in the Solar System with an enigmatic white spot, or should I say, white arc. It’s Wunda Crater on Uranus’ crater-blasted moon Umbriel. The 131-mile-wide crater, situated on the moon’s equator, is named for Wunda, a dark spirit in Aboriginal mythology. But on its floor is a bright feature about 6 miles (10 km) wide. We still don’t know what that one is either!

The moon Umbriel, 727 miles in diameter, with Wunda Crater and its bright internal ring of unknown origin. The moon's equator is vertical in this photo. Credit: NASA — The moon Umbriel, 727 miles in diameter, with Wunda Crater and its bright internal ring of unknown origin. The moon’s equator is vertical in this photo. Credit: NASA

May 15, 2015December 23, 2015 by Bob King

Andromeda and Milky Way Might Collide Sooner Than We Think

Andromeda's halo is gargantuan. Extending millions of light years, if we could see in our night sky it would be 100 times the diameter of the Moon or 50 degrees across! Credit: NASA

The merger of the Milky Way and Andromeda galaxy won’t happen for another 4 billion years, but the recent discovery of a massive halo of hot gas around Andromeda may mean our galaxies are already touching. University of Notre Dame astrophysicist Nicholas Lehner led a team of scientists using the Hubble Space Telescope to identify an enormous halo of hot, ionized gas at least 2 million light years in diameter surrounding the galaxy.

The Andromeda Galaxy is the largest member of a ragtag collection of some 54 galaxies, including the Milky Way, called the Local Group. With a trillion stars — twice as many as the Milky Way — it shines 25% brighter and can easily be seen with the naked eye from suburban and rural skies.

Quasars are distant, brilliant sources of light, believed to occur when a massive black hole in the center of a galaxy feeds on gas and stars. As the black hole consumes the material, it emits intense radiation, which is then detected as a quasar. These photos, taken by Hubble, show them as brilliant "stars" in the cores of six different galaxies. Credit: NASA/ESA — Six examples of quasars photographed with the Hubble. Quasars are distant, brilliant sources of light, believed to occur when a massive black hole in the center of a galaxy feeds on gas and stars. As the black hole consumes the material, it emits intense radiation, which is then detected as a quasar. Lehner and team measured Andromeda’s halo by studying how its gas affected the light from 18 different quasars. Credit: NASA/ESA

Think about this for a moment. If the halo extends at least a million light years in our direction, our two galaxies are MUCH closer to touching that previously thought. Granted, we’re only talking halo interactions at first, but the two may be mingling molecules even now if our galaxy is similarly cocooned.

Lehner describes halos as the “gaseous atmospheres of galaxies”. Despite its enormous size, Andromeda’s nimbus is virtually invisible. To find and study the halo, the team sought out quasars, distant star-like objects that radiate tremendous amounts of energy as matter funnels into the supermassive black holes in their cores. The brightest quasar, 3C273 in Virgo, can be seen in a 6-inch telescope! Their brilliant, pinpoint nature make them perfect probes.

To detect Andromeda's halo, Lehner and team studied how the light of 18 quasars (five shown here) was absorbed by the galaxy's gas. Credit: NASA — To detect Andromeda’s halo, Lehner and team studied how the light of 18 quasars (five shown here) was absorbed by the galaxy’s gas. Credit: NASA

“As the light from the quasars travels toward Hubble, the halo’s gas will absorb some of that light and make the quasar appear a little darker in just a very small wavelength range,” said J. Christopher Howk , associate professor of physics at Notre Dame and co-investigator. “By measuring the dip in brightness, we can tell how much halo gas from M31 there is between us and that quasar.”

Astronomers have observed halos around 44 other galaxies but never one as massive as Andromeda where so many quasars are available to clearly define its extent. The previous 44 were all extremely distant galaxies, with only a single quasar or data point to determine halo size and structure.

Andromeda’s close and huge with lots of quasars peppering its periphery. The team drew from about five years’ worth of observations of archived Hubble data to find many of the 18 objects needed for a good sample.

This illustration shows a stage in the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. In this image, representing Earth's night sky in 3.75 billion years, Andromeda (left) fills the field of view and begins to distort the Milky Way with tidal pull. (Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger) — This illustration shows a stage in the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. In this image, representing Earth’s night sky in 3.75 billion years, Andromeda (left) fills the field of view and begins to distort the Milky Way with tidal pull. Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger

The halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself, in the form of a hot, diffuse gas. Simulations suggest that it formed at the same time as the rest of the galaxy. Although mostly composed of ionized hydrogen — naked protons and electrons — Andromeda’s aura is also rich in heavier elements, probably supplied by supernovae. They erupt within the visible galaxy and violently blow good stuff like iron, silicon, oxygen and other familiar elements far into space. Over Andromeda’s lifetime, nearly half of all the heavy elements made by its stars have been expelled far beyond the galaxy’s 200,000-light-year-diameter stellar disk.

You might wonder if galactic halos might account for some or much of the still-mysterious dark matter. Probably not. While dark matter still makes up the bulk of the solid material in the universe, astronomers have been trying to account for the lack of visible matter in galaxies as well. Halos now seem a likely contributor.

The next clear night you look up to spy Andromeda, know this: It’s closer than you think!

For more on the topic, here are links to Lehner’s paper in the Astrophysical Journal and the Hubble release.

April 23, 2015December 23, 2015 by Nancy Atkinson

Hubble Telescope Celebrates 25 Years in Space With Spectacular New Image

This NASA/ESA Hubble Space Telescope image of the cluster Westerlund 2 and its surroundings has been released to celebrate Hubble’s 25th year in orbit and a quarter of a century of new discoveries, stunning images and outstanding science. Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team.

Images from space don’t get any prettier than this. A new image from the Hubble Space Telescope was released today to commemorate a quarter century of exploring the Solar System and beyond since the launch of the telescope on April 24, 1990. It shows a giant cluster of about 3,000 stars called Westerlund 2, located 20,000 light-years away from Earth in the constellation Carina. NASA describes the new image as a “brilliant tapestry of young stars flaring to life resemble a glittering fireworks display.”

The Hubble Teams are giving away a few “gifts” to everyone to celebrate this silver anniversary — see below!

“Hubble has completely transformed our view of the universe, revealing the true beauty and richness of the cosmos” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate. “This vista of starry fireworks and glowing gas is a fitting image for our celebration of 25 years of amazing Hubble science.”

The cluster is named after Swedish astronomer Bengt Westerlund who discovered the grouping in the 1960s.

You can get access to larger versions of the image here at ESA’s Hubble website, or at NASA’s HubbleSite.

There are anniversary events occurring around the US and the world. Here is a listing of at the Hubble anniversary site, where people can also find science articles, educational resources, downloadable presentations, and more:

And here’s a downloadable 25th anniversary gift for everyone: Hubble is offering a free ebook of 25 of Hubble’s most significant images, which can be found at this link or at iTunes.

See a stunning gallery of all the ‘anniversary’ images that have been released by the Hubble teams over the last 25 years at this Flickr gallery.

And finally, here’s an excellent visualization of a flight to the star cluster Westerlund 2:

April 1, 2015December 23, 2015 by Nancy Atkinson

Gallery: Behind the Scenes Images of the Final Hubble Servicing Mission

Hubble Servicing Mission astronaut training in the water of the Neutral Buoyancy Lab in Houston, Texas, February 2009. Credit and copyright: Michael Soluri.

Photographer Michael Soluri was granted unprecedented access to document the people and events behind the final Hubble Space Telescope Servicing Mission 4, STS-125, which launched in 2009. He has published these images in a new book, “Infinite Worlds: People & Places of Space Exploration.” Soluri has provided Universe Today with an exclusive gallery of images from the book, and also told us about his experiences in being able to follow for three years the behind the scenes lead-up to the mission.

Read his account and see more images below. You can read our full review of Infinite Worlds here.

K. Megan McArthur (PH.D.), the STS-125 Hubble SM4 Robotic Arm engineer during final servicing mission to Hubble, May 2009. Credit and copyright: Michael Soluri.

From a very early age following the space program and over the decades as a documentary photographer on location at various NASA flight centers, I always felt something was missing: an honest, unscripted visual sense of the people behind the scenes that make human and robotic space flight possible.

Yes, it’s always inspiring to experience and photograph a rocket launch with remote equipment or from 3 miles away. However, the access pattern over time has been the same. Writers and photographers herded together into controlled situations that in the end capture the same shot. Given security issues, this is understandable and the results over the decades are predictable.

To achieve the results experienced in Infinite Worlds required earning the trust of both the crew as well as Hubble and shuttle flight management. That trust contributed to being asked by the STS-125 crew to coach them in making better more visually communicative images of their experiences at Hubble. It also enabled me to be a part of and be accepted into the many worlds of that mission during good times and challenging ones.

The edited results comprise my book and exhibitions. Looking back on that journey, I am humbled by the mutual respect and trust extended to me by a remarkable, “made in the USA” labor force that for the most part no longer exists.

— Michael Soluri

Mark Turczyn, Hubble Space Telescope Senior Systems Engineer. In 'Infinite Worlds' he said, ""Every time we ran out of time … we created more." Credit and copyright: Michael Soluri. — Mark Turczyn, Hubble Space Telescope Senior Systems Engineer. In ‘Infinite Worlds’ he said, “”Every time we ran out of time … we created more.” Credit and copyright: Michael Soluri.

Office white-board of Mark Turczyn, HST Senior Systems Engineer. Credit and copyright: Michael Soluri.

Greg Cecil, a Thermal Protection Systems Technician, replaced and caulked damaged tiles on the cockpit area of the space shuttle. He is currently a middle school science teacher. Credit and copyright: Michael Soluri.

Christy Hansen, EVA Task Lead and STS-125 SM4 astronaut Drew Feustel in cargo bay of Atlantis in July 2008. Credit and copyright: Michael Soluri.

Four of the "space-walking" astronauts and their mission trainers reviewing one of the tool boxes they will be accessing in the cargo bay of the shuttle during the last service mission to the Hubble Space Telescope. Credit and copyright: Michael Soluri. — Four of the “space-walking” astronauts and their mission trainers reviewing one of the tool boxes they will be accessing in the cargo bay of the shuttle during the last service mission to the Hubble Space Telescope. Credit and copyright: Michael Soluri.

Mini Power Drill System, designed at NASA Goddard SpaceFlight Center used by astronauts on the final mission to the Hubble Space Telescope, May 2009. Credit and copyright: Michael Soluri.

The astronaut EVA crew of Hubble SM4 - last servicing mission to the Hubble by a space shuttle crew. From left to right: John Grunsfeld, Drew Feustel, Michael Good, and Mike Massimino. Image taken at Goddard Space Flight Center, July 2008. Credit and copyright: Michael Soluri. — The astronaut EVA crew of Hubble SM4 – last servicing mission to the Hubble by a space shuttle crew. From left to right: John Grunsfeld, Drew Feustel, Michael Good, and Mike Massimino. Image taken at Goddard Space Flight Center, July 2008. Credit and copyright: Michael Soluri.

John Grunsfeld, just before entering shuttle Atlantis for his fifth mission in space and his third to the Hubble Space Telescope. Grunsfeld wrote "Climbing Mountains" for Infinite Worlds. Credit and copyright: Michael Soluri. — John Grunsfeld, just before entering shuttle Atlantis for his fifth mission in space and his third to the Hubble Space Telescope. Grunsfeld wrote “Climbing Mountains” for Infinite Worlds. Credit and copyright: Michael Soluri.

Atlantis just after roll out and pad lock down at Pad 39A at Kennedy Space Center for the STS-125 Hubble Servicing Mission. March 31, 2009. Credit and copyright: Michael Soluri.

Jill McGuire, Manager, Hubble SM4 Crew Aids and Tools, in Mission control in Houson during EVA 4, May 2009. Credit and copyright: Michael Soluri.

Self Portrait by John Grunsfeld and shuttle Atlantis on the Hubble Space Telescope -- orbiting Earth. Image courtesy Michael Soluri. — Self Portrait by John Grunsfeld and shuttle Atlantis on the Hubble Space Telescope — orbiting Earth. Image courtesy Michael Soluri.

Several of Soluri’s images of the SM4’s EVA tools and photos by the Atlantis crew are part of an exhibition at the Smithsonian Air and Space Museum Outside the Spacecraft: 50 Years of Extra-Vehicular Activity, on view at the Air and Space Museum through June 8. There’s also an online exhibition. Smithsonian Associates is the presenting organization.

Soluri will give a presentation and do a book signing on April 11, 2015 at the Smithsonian’s Hirshhorn Museum & Sculpture Garden. Soluri will be joined by four individuals who played key roles in Service Mission SM4: astronaut Scott Altman, the STS-125 shuttle commander; David Leckrone, senior project scientist; Christy Hansen, EVA spacewalk flight controller and astronaut instructor; and Hubble systems engineer Ed Rezac. More information on that event can be found here.

April 1, 2015December 23, 2015 by Tyler Simko

Book Review: “Infinite Worlds: People & Places of Space Exploration” by Michael Soluri

Infinite Worlds - People & Places of Space Exploration: by Michael Soluri, Foreword by John Glenn. Cover image courtesy of Michael Soluri and Simon & Schuster.

On April 24, 1990, the Hubble Space Telescope was launched from Kennedy Space Center into low Earth orbit. Hubble was the first telescope designed to operate in space, so it was able to avoid interference from Earth’s atmosphere – an inconvenience that had limited astronomers since they first looked up to the skies. However, scientists quickly realized that something was wrong; the images were blurry. Despite being among the most precisely ground instruments ever made, the primary mirror in the Hubble was about 2,200 nanometers too flat at the perimeter (for reference, the width of a typical sheet of paper is about 100,000 nanometers). Luckily, there was a solution.

Hubble was designed to be serviced in space. As NASA writes on the telescope’s website, “a series of small mirrors could be used to intercept the light reflecting off the mirror, correct for the flaw, and bounce the light to the telescope’s science instruments.” A series of five missions lasting from 1993 to 2009 was devised to correct the mirror and perform various upgrades. Despite being the first of their kind, the missions were declared a resounding success – and they enabled the Hubble Space Telescope to remain operational to this day. Many of Hubble’s images are among the most incredible ever produced by mankind, yet few people know anything about the remarkable men and women who made them possible.

ohn Grunsfeld, just before entering shuttle Atlantis for his fifth mission in space and his third to the Hubble Space Telescope. Grunsfeld wrote "Climbing Mountains" for Infinite Worlds. Credit and copyright: Michael Soluri. — ohn Grunsfeld, just before entering shuttle Atlantis for his fifth mission in space and his third to the Hubble Space Telescope. Grunsfeld wrote “Climbing Mountains” for Infinite Worlds. Credit and copyright: Michael Soluri.

See an exclusive gallery of images from the book here.

Infinite Worlds: People & Places of Space Exploration, the latest book from photographer Michael Soluri, documents the people who worked on the last of these repair missions, STS-125 (also known as Hubble Space Telescope Servicing Mission 4 [HST-SM4]). The nearly two-week journey aboard Space Shuttle Atlantis saw the successful installation of two new instruments and the repair of two others. Like the four other shuttle crews that came before them, the men and women aboard STS-125 enabled Hubble to see deeper and farther into the past than ever before.

Michael Massimino, a veteran of the earlier STS-109 mission, is one of these people. Massimino and Soluri became fast friends after a chance encounter, when Soluri asked: “What is the quality of light really like in space?” Following their discussion, Massimino asked Soluri to teach him and the rest of the crew how to take photographs that would better communicate their experiences in space. Astronauts are always taking pictures, but the lighting in space is, understandably, not always ideal. Like Soluri himself in Infinite Worlds, the astronauts repairing Hubble were looking for better ways to communicate the beauty of space travel through photography.

Soluri was granted unprecedented access to document the people and events behind the mission throughout a period of more than four years. The photographs in the book “give deserved attention to a few of the many thousands of people who worked on the Space Shuttle and Hubble Space Telescope programs,” reads an inspiring foreword by John Glenn, the first American to orbit the Earth. Infinite Worlds reveals a side of space travel that most of us would never otherwise see, including the training sessions, tools, and trials that make success possible. NASA, notorious for keeping their employees tightly scripted and inaccessible, rarely grants such access – and with the closing of the Space Shuttle Program in 2011, such intimacy may never be seen again.

Science is a cooperative discipline, but most people only ever see the results. The tireless work of thousands of individuals is often taken for granted and forgotten. Although many people still hold the false idea that scientific accomplishments are made by individual geniuses working in an armchair, now more than ever before we are entering an age where science is performed by large teams working cooperatively. To mention just one example, CERN hosts scientists of more than 100 nationalities. As Jill McGuire, a manager at Goddard Space Flight Center, writes about the field in the book, “the best way to move forward in the business was to get my hands dirty by working with the skilled machinists and technicians in the branch to learn everything I could.”

Infinite Worlds grants readers an exhilarating glimpse into this cooperative world. One particularly inspiring section follows the immediate buildup to the launch of STS-125. The transcript of the pre-launch quality check is paralleled by images of the situation as it happened. Black and white photographs from both cockpit and control room highlight the tension behind “the most risky thing NASA does,” according to Space Shuttle Launch Director Michael Leinbach. He continues, “they were real people with real families, real children, real lives.” Infinite Worlds reminds us of this: the work behind every scientific breakthrough is not magic, but rather the result of talented and dedicated individuals.

As we approach the 25th anniversary of the Hubble Space Telescope’s launch and look to the future, a book like Infinite Worlds is more relevant now than ever before. The beautiful photographs in Soluri’s book tell two kindred stories: not only the heroic report of repairing a multi-billion dollar piece of equipment, but also a unique glimpse at the inspiring men and women who made it all possible. Whether humanity’s next missions are to Mars, Europa, or elsewhere, one thing will remain constant – we will only reach the stars through the work of exceptional people.

Infinite Worlds is available at Amazon, Barnes and Noble, Indiebound, iBooks, and Google Play.

Learn more about Michael Soluri at his website.

Several of Soluri’s images of the SM4’s EVA tools and photos by the Atlantis crew are part of an exhibition at the Smithsonian Air and Space Museum, Outside the Spacecraft: 50 Years of Extra-Vehicular Activity, on view at the Air and Space Museum through June 8. There’s also an online exhibition.

February 20, 2015December 23, 2015 by Vanessa Janek

How Can Space Travel Faster Than The Speed Of Light?

What would you see at the speed of light/

Cosmologists are intellectual time travelers. Looking back over billions of years, these scientists are able to trace the evolution of our Universe in astonishing detail. 13.8 billion years ago, the Big Bang occurred. Fractions of a second later, the fledgling Universe expanded exponentially during an incredibly brief period of time called inflation. Over the ensuing eons, our cosmos has grown to such an enormous size that we can no longer see the other side of it.

But how can this be? If light’s velocity marks a cosmic speed limit, how can there possibly be regions of spacetime whose photons are forever out of our reach? And even if there are, how do we know that they exist at all?

The Expanding Universe

Like everything else in physics, our Universe strives to exist in the lowest possible energy state possible. But around 10^-36 seconds after the Big Bang, inflationary cosmologists believe that the cosmos found itself resting instead at a “false vacuum energy” – a low-point that wasn’t really a low-point. Seeking the true nadir of vacuum energy, over a minute fraction of a moment, the Universe is thought to have ballooned by a factor of 10⁵⁰.

Since that time, our Universe has continued to expand, but at a much slower pace. We see evidence of this expansion in the light from distant objects. As photons emitted by a star or galaxy propagate across the Universe, the stretching of space causes them to lose energy. Once the photons reach us, their wavelengths have been redshifted in accordance with the distance they have traveled.

Two sources of redshift: Doppler and cosmological expansion; modeled after Koupelis & Kuhn. Credit: Brews Ohare. — Two sources of redshift: Doppler and cosmological expansion; modeled after Koupelis & Kuhn. Bottom: Detectors catch the light that is emitted by a central star. This light is stretched, or redshifted, as space expands in between. Credit: Brews Ohare.

This is why cosmologists speak of redshift as a function of distance in both space and time. The light from these distant objects has been traveling for so long that, when we finally see it, we are seeing the objects as they were billions of years ago.

The Hubble Volume

Redshifted light allows us to see objects like galaxies as they existed in the distant past; but we cannot see all events that occurred in our Universe during its history. Because our cosmos is expanding, the light from some objects is simply too far away for us ever to see.

The physics of that boundary rely, in part, on a chunk of surrounding spacetime called the Hubble volume. Here on Earth, we define the Hubble volume by measuring something called the Hubble parameter (H₀), a value that relates the apparent recession speed of distant objects to their redshift. It was first calculated in 1929, when Edwin Hubble discovered that faraway galaxies appeared to be moving away from us at a rate that was proportional to the redshift of their light.

Fit of redshift velocities to Hubble's law. Credit: Brews Ohare — Fit of redshift velocities to Hubble’s law. Credit: Brews Ohare

Dividing the speed of light by H₀, we get the Hubble volume. This spherical bubble encloses a region where all objects move away from a central observer at speeds less than the speed of light. Correspondingly, all objects outside of the Hubble volume move away from the center faster than the speed of light.

Yes, “faster than the speed of light.” How is this possible?

The Magic of Relativity

The answer has to do with the difference between special relativity and general relativity. Special relativity requires what is called an “inertial reference frame” – more simply, a backdrop. According to this theory, the speed of light is the same when compared in all inertial reference frames. Whether an observer is sitting still on a park bench on planet Earth or zooming past Neptune in a futuristic high-velocity rocketship, the speed of light is always the same. A photon always travels away from the observer at 300,000,000 meters per second, and he or she will never catch up.

General relativity, however, describes the fabric of spacetime itself. In this theory, there is no inertial reference frame. Spacetime is not expanding with respect to anything outside of itself, so the the speed of light as a limit on its velocity doesn’t apply. Yes, galaxies outside of our Hubble sphere are receding from us faster than the speed of light. But the galaxies themselves aren’t breaking any cosmic speed limits. To an observer within one of those galaxies, nothing violates special relativity at all. It is the space in between us and those galaxies that is rapidly proliferating and stretching exponentially.

The Observable Universe

Now for the next bombshell: The Hubble volume is not the same thing as the observable Universe.

To understand this, consider that as the Universe gets older, distant light has more time to reach our detectors here on Earth. We can see objects that have accelerated beyond our current Hubble volume because the light we see today was emitted when they were within it.

Strictly speaking, our observable Universe coincides with something called the particle horizon. The particle horizon marks the distance to the farthest light that we can possibly see at this moment in time – photons that have had enough time to either remain within, or catch up to, our gently expanding Hubble sphere.

And just what is this distance? A little more than 46 billion light years in every direction – giving our observable Universe a diameter of approximately 93 billion light years, or more than 500 billion trillion miles.

The observable - or inferrable universe. This may just be a small component of the whole ball game. — The observable universe, more technically known as the particle horizon.

(A quick note: the particle horizon is not the same thing as the cosmological event horizon. The particle horizon encompasses all the events in the past that we can currently see. The cosmological event horizon, on the other hand, defines a distance within which a future observer will be able to see the then-ancient light our little corner of spacetime is emitting today.

In other words, the particle horizon deals with the distance to past objects whose ancient light that we can see today; the cosmological event horizon deals with the distance that our present-day light that will be able to travel as faraway regions of the Universe accelerate away from us.)

Dark Energy

Thanks to the expansion of the Universe, there are regions of the cosmos that we will never see, even if we could wait an infinite amount of time for their light to reach us. But what about those areas just beyond the reaches of our present-day Hubble volume? If that sphere is also expanding, will we ever be able to see those boundary objects?

This depends on which region is expanding faster – the Hubble volume or the parts of the Universe just outside of it. And the answer to that question depends on two things: 1) whether H₀ is increasing or decreasing, and 2) whether the Universe is accelerating or decelerating. These two rates are intimately related, but they are not the same.

In fact, cosmologists believe that we are actually living at a time when H₀is decreasing; but because of dark energy, the velocity of the Universe’s expansion is increasing.

That may sound counterintuitive, but as long as H₀decreases at a slower rate than that at which the Universe’s expansion velocity is increasing, the overall movement of galaxies away from us still occurs at an accelerated pace. And at this moment in time, cosmologists believe that the Universe’s expansion will outpace the more modest growth of the Hubble volume.

So even though our Hubble volume is expanding, the influence of dark energy appears to provide a hard limit to the ever-increasing observable Universe.

Our Earthly Limitations

Cosmologists seem to have a good handle on deep questions like what our observable Universe will someday look like and how the expansion of the cosmos will change. But ultimately, scientists can only theorize the answers to questions about the future based on their present-day understanding of the Universe. Cosmological timescales are so unimaginably long that it is impossible to say much of anything concrete about how the Universe will behave in the future. Today’s models fit the current data remarkably well, but the truth is that none of us will live long enough to see whether the predictions truly match all of the outcomes.

Disappointing? Sure. But totally worth the effort to help our puny brains consider such mind-bloggling science – a reality that, as usual, is just plain stranger than fiction.

February 6, 2015December 23, 2015 by Nancy Atkinson

Sadly, There won’t be a LEGO Hubble Space Telescope

A proposed LEGO version of the Hubble Space Telescope won't be produced, Credit: LEGO.

This week the official LEGO review board announced their newest official LEGO model kits that were chosen from fan-suggested ideas, submitted through its LEGO Ideas website. While a Hubble Space Telescope kit seemed an obvious choice (this year is Hubble’s 25th anniversary), instead the review board chose a Pixar WALL-E robot set and a Doctor Who set.

“We reviewed eight amazing projects that reached 10,000 supporters between June and September,” said Signe Lonholdt from the LEGO Ideas team said in a video (below) announcing the winners. The eight sets had each reached 10,000 fan votes, which Lonholdt said is a “tremendous accomplishment,” but the final decision is up to the review board. The board considers factors such as “playability, safety and fit within the LEGO brand.”

The LEGO Hubble Space Telescope set was designed and submitted by fan Gabriel Russo, who said the kit would be “the perfect homage to its 25th anniversary in 2015.” According to Robert Pearlman at collectSpace.com, it reached 10,000 votes last August. You can see the Hubble submission page here.

Other fan-submitted ideas that didn’t make the cut were three different Star Wars sets (an AT-AT, a Lightsaber set and an Invisible Hand set) along with a Ghostbusters HQ building.

Previous space-related fan-created/submitted kits that were chosen and produced by LEGO are models of Japan’s Hayabusa spacecraft and NASA’s Mars Curiosity rover.

You can see other submitted ideas and vote for them on the LEGO Ideas site.

Source: LEGO