This Star Has Reached the End of its Life

About 10,000 light years away, in the constellation Centaurus, is a planetary nebula called NGC 5307. A planetary nebula is the remnant of a star like our Sun, when it has reached what can be described as the end of its life. This Hubble image of NGC 5307 not only makes you wonder about the star’s past, it makes you ponder the future of our very own Sun.

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16 Years of Hubble Images Come Together in this one Picture Containing 265,000 Galaxies

Even after almost three decades of faithful service, the Hubble Space Telescope continues to operate and provide breathtaking images of the cosmos. As one of NASA’s Great Observatories, its observations of distant galaxies, exoplanets, and the expansion of the Universe have had a revolutionary impact on astronomy, astrophysics and cosmology.

Hubble’s latest contribution comes in the form of a deep-sky mosaic image that was constructed using 16 years’ worth of observations. Known as the “Hubble Legacy Field“, this mosaic is being described as the largest and most comprehensive “history book” of galaxies. All told, it contains roughly 265,000 galaxies that date back to just 500 million years after the Big Bang.

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This is What It’ll Look Like When the Milky Way and Andromeda Galaxies Collide Billions of Years from Now

Located in the constellation of Hercules, about 230 million light-years away, NGC 6052 is a pair of colliding galaxies. Image Credit: ESA/Hubble & NASA, A. Adamo et al.

What happens when two galaxies collide? The Milky Way and the Andromeda Galaxy are on a collision course, and in about 4.5 billion years, they will meet. Now astronomers using the Hubble have provided some visual insight into what that collision might look like.

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How Fast is the Universe Expanding? Hubble and Gaia Team Up to Conduct the Most Accurate Measurements to Date

In the 1920s, Edwin Hubble made the groundbreaking discovery that the Universe was in a state of expansion. Originally predicted as a consequence of Einstein’s Theory of General Relativity, measurements of this expansion came to be known as Hubble’s Constant. Today, and with the help of next-generation telescopes – like the aptly-named Hubble Space Telescope (HST) – astronomers have remeasured and revised this law many times.

These measurements confirmed that the rate of expansion has increased over time, though scientists are still unsure why. The latest measurements were conducted by an international team using Hubble, who then compared their results with data obtained by the European Space Agency’s (ESA) Gaia observatory. This has led to the most precise measurements of the Hubble Constant to date, though questions about cosmic acceleration remain.

The study which describes their findings appeared in the July 12th issue of the Astrophysical Journal, titled “Milky Way Cepheid Standards for Measuring Cosmic Distances and Application to Gaia DR2: Implications for the Hubble Constant.” The team behind the study included members from the Space Telescope Science Institute (STScI), the Johns Hopkins University, the National Institute for Astrophysics (INAF), UC Berkeley, Texas A&M University, and the European Southern Observatory (ESO).

This illustration shows three steps astronomers used to measure the universe’s expansion rate (Hubble constant) to an unprecedented accuracy. Credits: NASA, ESA, A. Feild (STScI), and A. Riess (STScI/JHU)

Since 2005, Adam Riess – a Nobel Laureate Professor with the Space Telescope Science Institute and the Johns Hopkins University – has been working to refine the Hubble Constant value by streamlining and strengthening the “cosmic distance ladder”. Along with his team, known as Supernova H0 for the Equation of State (SH0ES), they have successfully reduced the uncertainty associated with the rate of cosmic expansion to just 2.2%

To break it down, astronomers have traditionally used the “cosmic distance ladder” to measure distances in the Universe. This consists of relying on distance markers like Cepheid variables in distant galaxies – pulsating stars whose distances can be inferred by comparing their intrinsic brightness with their apparent brightness. These measurements are then compared to the way light from distant galaxies is redshifted to determine how fast the space between galaxies is expanding.

From this, the Hubble Constant is derived. Another method that is used is to observe the Cosmic Microwave Background (CMB) to trace the expansion of the cosmos during the early Universe – circa. 378,000 years after the Big Bang – and then using physics to extrapolate that to the present expansion rate. Together, the measurements should provide an end-to-end measurement of how the Universe has expanded over time.

However, astronomers have known for some time that the two measurements don’t match up. In a previous study, Riess and his team conducted measurements using Hubble to obtain a Hubble Constant value of 73 km/s (45.36 mps) per megaparsec (3.3 million light-years). Meanwhile, results based on the ESA’ Planck observatory (which observed the CMB between 2009 and 2013) predicted that the Hubble constant value should now be 67 km/s (41.63 mps) per megaparsec and no higher than 69 km/s (42.87 mps) – which represents a discrepancy of 9%.

A multi-color all-sky image of the microwave sky. Credit: ESA, HFI and LFI consortia

As Riess indicated in a recent NASA press release:

“The tension seems to have grown into a full-blown incompatibility between our views of the early and late time universe. At this point, clearly it’s not simply some gross error in any one measurement. It’s as though you predicted how tall a child would become from a growth chart and then found the adult he or she became greatly exceeded the prediction. We are very perplexed.”

In this case, Riess and his colleagues used Hubble to gauge the brightness of distant Cepheid variables while Gaia provided the parallax information – the apparent change in an objects position based on different points of view – needed to determine the distance. Gaia also added to the study by measuring the distance to 50 Cepheid variables in the Milky Way, which were combined with brightness measurements from Hubble.

This allowed the astronomers to more accurately calibrate the Cepheids and then use those seen outside the Milky Way as milepost markers. Using both the Hubble measurements and newly released data from Gaia, Riess and his colleagues were able to refine their measurements on the present rate of expansion to 73.5 kilometers (45.6 miles) per second per megaparsec.

ESA’s Gaia is currently on a five-year mission to map the stars of the Milky Way. Image credit: ESA/ATG medialab; background: ESO/S. Brunier.

As Stefano Casertano, of the Space Telescope Science Institute and a member of the SHOES team, added:

“Hubble is really amazing as a general-purpose observatory, but Gaia is the new gold standard for calibrating distance. It is purpose-built for measuring parallax—this is what it was designed to do. Gaia brings a new ability to recalibrate all past distance measures, and it seems to confirm our previous work. We get the same answer for the Hubble constant if we replace all previous calibrations of the distance ladder with just the Gaia parallaxes. It’s a crosscheck between two very powerful and precise observatories.”

Looking to the future, Riess and his team hope to continue to work with Gaia so they can reduce the uncertainty associated with the value of the Hubble Constant to just 1% by the early 2020s. In the meantime, the discrepancy between modern rates of expansion and those based on the CMB will continue to be a puzzle to astronomers.

In the end, this may be an indication that other physics are at work in our Universe, that dark matter interacts with normal matter in a way that is different than what scientists suspect, or that dark energy could be even more exotic than previously thought. Whatever the cause, it is clear the Universe still has some surprises in store for us!

Further Reading: NASA

Neptune’s Huge Storm Is Shrinking Away In New Images From Hubble

Back in the late 1980’s, Voyager 2 was the first spacecraft to capture images of the giant storms in Neptune’s atmosphere. Before then, little was known about the deep winds cycling through Neptune’s atmosphere. But Hubble has been turning its sharp eye towards Neptune over the years to study these storms, and over the past couple of years, it’s watched one enormous storm petering out of existence.

“It looks like we’re capturing the demise of this dark vortex, and it’s different from what well-known studies led us to expect.” – Michael H. Wong, University of California at Berkeley.

When we think of storms on the other planets in our Solar System, we automatically think of Jupiter. Jupiter’s Great Red Spot is a fixture in our Solar System, and has lasted 200 years or more. But the storms on Neptune are different: they’re transient.

Voyager 2 captured this image of Neptune in 1982, when it was over 7 million km (4.4 million miles) away from the planet. The Great Dark Spot in the middle of the image was the first storm ever seen on Neptune. Image: By NASA (JPL image) [Public domain], via Wikimedia Commons

The storm on Neptune moves in an anti-cyclonic direction, and if it were on Earth, it would span from Boston to Portugal. Neptune has a much deeper atmosphere than Earth—in fact it’s all atmosphere—and this storm brings up material from deep inside. This gives scientists a chance to study the depths of Neptune’s atmosphere without sending a spacecraft there.

The first question facing scientists is ‘What is the storm made of?’ The best candidate is a chemical called hydrogen sulfide (H2S). H2S is a toxic chemical that stinks like rotten eggs. But particles of H2S are not actually dark, they’re reflective. Joshua Tollefson from the University of California at Berkeley, explains: “The particles themselves are still highly reflective; they are just slightly darker than the particles in the surrounding atmosphere.”

“We have no evidence of how these vortices are formed or how fast they rotate.” – Agustín Sánchez-Lavega, University of the Basque Country in Spain.

But beyond guessing what chemical the spot might me made of, scientists don’t know much else. “We have no evidence of how these vortices are formed or how fast they rotate,” said Agustín Sánchez-Lavega from the University of the Basque Country in Spain. “It is most likely that they arise from an instability in the sheared eastward and westward winds.”

There’ve been predictions about how storms on Neptune should behave, based on work done in the past. The expectation was that storms like this would drift toward the equator, then break up in a burst of activity. But this dark storm is on its own path, and is defying expectations.

“We thought that once the vortex got too close to the equator, it would break up and perhaps create a spectacular outburst of cloud activity.” – Michael H. Wong, University of California at Berkeley.

“It looks like we’re capturing the demise of this dark vortex, and it’s different from what well-known studies led us to expect,” said Michael H. Wong of the University of California at Berkeley, referring to work by Ray LeBeau (now at St. Louis University) and Tim Dowling’s team at the University of Louisville. “Their dynamical simulations said that anticyclones under Neptune’s wind shear would probably drift toward the equator. We thought that once the vortex got too close to the equator, it would break up and perhaps create a spectacular outburst of cloud activity.”

Rather than going out in some kind of notable burst of activity, this storm is just fading away. And it’s also not drifting toward the equator as expected, but is making its way toward the south pole. Again, the inevitable comparison is with Jupiter’s Great Red Spot (GRS).

The GRS is held in place by the prominent storm bands in Jupiter’s atmosphere. And those bands move in alternating directions, constraining the movement of the GRS. Neptune doesn’t have those bands, so it’s thought that storms on Neptune would tend to drift to the equator, rather than toward the south pole.

Jupiter’s prominent storm, the Great Red Spot, is held in place by the alternating storm bands in Jupiter’s atmosphere. Image: By NASA, ESA, and A. Simon (Goddard Space Flight Center) [Public domain], via Wikimedia Commons

This isn’t the first time that Hubble has been keeping an eye on Neptune’s storms. The Space Telescope has also looked at storms on Neptune in 1994 and 1996. The video below tells the story of Hubble’s storm watching mission.

The images of Neptune’s storms are from the Hubble Outer Planets Atmosphere Legacy (OPAL) program. OPAL gathers long-term baseline images of the outer planets to help us understand the evolution and atmospheres of the gas giants. Images of Jupiter, Saturn, Uranus and Neptune are being taken with a variety of filters to form a kind of time-lapse database of atmospheric activity on the four gas planets.

NASA Completes Critical Space Communications Network with Spectacular Launch of Final TDRS Science Relay Satellite

NASA’s Tracking and Data Relay Satellite-M (TDRS-M), which is the third and final in a series of next generation science communications satellites, was successfully launched Aug. 18, 2017 at 8:29 a.m. EDT by a United Launch Alliance (ULA) Atlas V rocket from Space Launch Complex-41 on Cape Canaveral Air Force Station in Florida. TDRS-M has been placed into orbit following separation from the upper stage. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – Today marked the end of an era for NASA as the last of the agency’s next generation Tracking and Data Relay Satellites (TRDS) that transmit the critical science data and communications for the Hubble Space Telescope and human spaceflight missions to the International Space Station, successfully rocketed to orbit this morning, Fri. Aug 18 from the Florida Space Coast.

The spectacular liftoff of the strangely fish-like TDRS-M science relay comsat atop a United Launch Alliance Atlas V rocket occurred at 8:29 a.m. EDT a.m. (2:29 GMT) Aug. 18 from Space Launch Complex 41 at Cape Canaveral Air Force Station.

The weather cooperated with relatively thin but artistic clouds and low winds and offered spectators a spectacular launch show that will not forget.

NASA’s $408 million next generation Tracking and Data Relay Satellites (TRDS) looks like a giant alien fish or cocooned creature. But actually plays an unparalleled role in relaying critical science measurements, research data and tracking observations gathered by the International Space Station (ISS), Hubble and a plethora of Earth science missions.

“TDRS is a critical national asset have because of its importance to the space station and all of our science missions, primarily the Hubble Space Telescope and Earth science missions that use TDRS,” said Tim Dunn, NASA’s TDRS-M launch director.

NASA’s Tracking and Data Relay Satellite-M (TDRS-M), which is the third and final in a series of next generation science communications satellites, was successfully launched Aug. 18, 2017 at 8:29 a.m. EDT by a United Launch Alliance (ULA) Atlas V rocket from Space Launch Complex-41 on Cape Canaveral Air Force Station in Florida. TDRS-M has been placed into orbit following separation from the upper stage. Credit: Ken Kremer/kenkremer.com

TDRS-M will provide high-bandwidth communications to spacecraft in low-Earth orbit. The TDRS network enables continuous communication with the International Space Station, the Hubble Space Telescope, the Earth Observing System and other programs supporting human space flight, said satellite builder Boeing, the prime contractor for the mission.

TDRS-M is the last of three satellites to be launched in the third generation of TDRS satellites. It is also the final satellite built based on Boeing’s 601 spacecraft bus series.

NASA plans to switch to much higher capacity laser communications for the next generation of TDRS-like satellites and therefore opted to not build a fourth third generation satellite after TDRS-M.

Inside the Astrotech payload processing facility in Titusville, FL,NASA’s massive, insect like Tracking and Data Relay Satellite, or TDRS-M, spacecraft is undergoing preflight processing during media visit on 13 July 2017. TDRS-M will transmit critical science data gathered by the ISS, Hubble and numerous NASA Earth science missions. It is being prepared for encapsulation inside its payload fairing prior to being transported to Launch Complex 41 at Cape Canaveral Air Force Station for launch on a United Launch Alliance (ULA) Atlas V rocket on 3 August 2017. Credit: Ken Kremer/kenkremer.com

“The TDRS fleet is a critical connection delivering science and human spaceflight data to those who can use it here on Earth,” said Dave Littmann, the TDRS project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“TDRS-M will expand the capabilities and extend the lifespan of the Space Network, allowing us to continue receiving and transmitting mission data well into the next decade.”

Launch of ULA Atlas V on TDRS-M mission for NASA from Cape Canaveral Air Force Station in Florida on Aug. 18, 2017 at 8:29 a.m. EDT. Credit: Julian Leek

TDRS-M joins a constellation of 9 TDRS satellites already in orbit and ups the fleet to ten orbiting satellites.

Evolution of NASA’s Tracking and Data Relay Satellite (TDRS) System. Credit: NASA

The Atlas V rocket and Centaur upper stage delivered TDRS-M to its desired preliminary orbit.
“Trajectory analysis in. Injection accuracy was within 1% of prediction #TDRSM,” tweeted ULA CEO Torey Bruno.

Several hours after the launch ground controllers reported the satellite was in good health.

On tap now is a four month period or orbit checkout by prime contractor Boeing as well as a series of five significant orbit raising maneuvers from its initial orbit to Geostationary orbit over the Pacific Ocean.

“This TDRS-M milestone is another step forward in Boeing’s commitment to developing technologies to support future NASA near-Earth, moon, Mars and deep space missions – and to do so affordably, drawing on our 40-plus years of strong Boeing-NASA partnership,” said Enrico Attanasio, executive director, Department of Defense and Civil Programs, Boeing Satellite Systems.

Ground controllers will then move it to its final orbit over the Atlantic Ocean.

NASA plans to conduct additional tests before putting TDRS-M into service early next year over the Atlantic.

Blastoff of NASA’s Tracking and Data Relay Satellite-M (TDRS-M) on Aug. 18, 2017 at 8:29 a.m. EDT by a United Launch Alliance (ULA) Atlas V rocket from Space Launch Complex-41 on Cape Canaveral Air Force Station in Florida – as seen from the VAB roof. Credit: Ken Kremer/kenkremer.com

The importance of the TDRS constellation of satellites can’t be overstated.

Virtually all the communications relay capability involving human spaceflight, such as the ISS, resupply vehicles like the SpaceX cargo Dragon and Orbital ATK Cygnus and the soon to launch human space taxis like crew Dragon, Boeing Starliner and NASA’s Orion deep space crew capsule route their science results voice, data, command, telemetry and communications via the TDRS network of satellites.

The TDRS constellation enables both space to space and space to ground communications for virtually the entire orbital period.

The two stage Atlas V rocket stands 191 feet tall.

TDRS-M, spacecraft, which stands for Tracking and Data Relay Satellite – M is NASA’s new and advanced science data relay communications satellite that will transmit research measurements and analysis gathered by the astronaut crews and instruments flying abroad the International Space Station (ISS), Hubble Space Telescope and over 35 NASA Earth science missions including MMS, GPM, Aura, Aqua, Landsat, Jason 2 and 3 and more.

The TDRS constellation orbits 22,300 miles above Earth and provide near-constant communication links between the ground and the orbiting satellites.

TRDS-M will have S-, Ku- and Ka-band capabilities. Ka has the capability to transmit as much as six-gigabytes of data per minute. That’s the equivalent of downloading almost 14,000 songs per minute says NASA.

The TDRS program is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

TDRS-M is the third satellite in the third series of NASA’s American’s most powerful and most advanced Tracking and Data Relay Satellites. It is designed to last for a 15 year orbital lifetime.

The first TDRS satellite was deployed from the Space Shuttle Challenger in 1983 as TDRS-A.

TDRS-M was built by prime contractor Boeing in El Segundo, California and is the third of a three satellite series – comprising TDRS -K, L, and M. They are based on the Boeing 601 series satellite bus and will be keep the TDRS satellite system operational through the 2020s.

TDSR-K and TDRS-L were launched in 2013 and 2014.

Configuration diagram of NASA’s Tracking and Data Relay Satellites. Credit: NASA

The Tracking and Data Relay Satellite project is managed at NASA’s Goddard Space Flight Center.

TDRS-M was built as a follow on and replacement satellite necessary to maintain and expand NASA’s Space Network, according to a NASA description.

The gigantic satellite is about as long as two school buses and measures 21 meters in length by 13.1 meters wide.

It has a dry mass of 1800 kg (4000 lbs) and a fueled mass of 3,454 kilogram (7,615 lb) at launch.

Watch for Ken’s continuing onsite TDRS-M, CRS-12, ORS 5 and NASA and space mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer