Art History NASA Style

This illustration of a double-cylinder space colony is from the 1970's, by artist Rick Guidice. Image: NASA Ames Research Center
This illustration of a double-cylinder space colony is from the 1970's, by artist Rick Guidice. Image: NASA Ames Research Center

To some, art and science are opposed to one another. Art is aesthetics, expression, and intuition, while science is all cold, hard, rational thought. But that’s a simplistic understanding. They’re both quintessential human endeavours, and they’re both part of the human spirit.

Some at NASA have always understood this, and there’s actually an interesting, collaborative history between NASA and the art world, that reaches back several decades. Not the kind of art that you see hanging in elite galleries in the world’s large cities, but the kind of art that documents achievements in space exploration, and that helps us envision what our future could be.

Mitchell Jamieson produced this painting of astronaut Gordon Cooper. Titled "First Steps", it documents Cooper's first steps after exiting his Mercury spacecraft in 1963, after Cooper had completed 22 orbits of Earth. Image Credit: Mitchell Jamieson/Courtesy of the Smithsonian National Air and Space Museum
Mitchell Jamieson produced this painting of astronaut Gordon Cooper. Titled “First Steps”, it documents Cooper’s first steps after exiting his Mercury spacecraft in 1963, after Cooper had completed 22 orbits of Earth. Image Credit: Mitchell Jamieson/Courtesy of the Smithsonian National Air and Space Museum

Back in 1962, when NASA was 4 years old, NASA administrator James Webb put the wheels in motion for a collaboration between NASA and American artists. Artist Bruce Stevenson had been commissioned to produce a portrait of Alan Shepard. Shepard, of course, was the first American in space. He piloted the first Project Mercury flight, MR-3, in 1961. When Webb saw it, he got a bright idea.

When Stevenson brought is portrait of Shepard to NASA headquarters, James Webb thought that Stevenson wanted to paint portraits of all seven Mercury astronauts. But Webb thought a group portrait would be even better. The group portrait was never produced, but it got Webb thinking. In a memo, he said “…we should consider in a deliberate way just what NASA should do in the field of fine arts to commemorate the …historic events” of the American space program.

That set in motion a framework that exists to this day. Beyond just portraits, Webb wanted artists to produce paintings that would convey the excitement around the entire endeavour of space flight, and what the deeper meaning behind it might be. He wanted artists to capture all of the excitement around the preparation and countdown for launches, and activities in space.

This 1963 painting by artist Paul Calle captures the lift-off of the Saturn V Moon rocket. Image: Paul Calle, NASA
This 1963 painting by artist Paul Calle captures the lift-off of the Saturn V Moon rocket. Image: Paul Calle, NASA

That’s when the NASA collaboration with artists began. A young artist named James Dean was assigned to the program, and he took a page out of the Air Force’s book, which established its own art program in 1954.

There’s a whole cast of characters involved, each one contributing to the success of the program. One such person was John Walker, Director of the National Gallery. He was enthusiastic, saying in a talk in 1965 that “the present space exploration effort by the United States will probably rank among the more important events in the history of mankind.” History has certainly proven those words to be true.

This Norman Rockwell painting is from 1965, and shows astronauts Gus Grissom and John Young suiting up for the first Gemini flight in March, 1965. NASA loaned Rockwell a spacesuit for the painting. Image: Norman Rockwell, NASA Art Program
This Norman Rockwell painting is from 1965, and shows astronauts Gus Grissom and John Young suiting up for the first Gemini flight in March, 1965. NASA loaned Rockwell a spacesuit for the painting. Image: Norman Rockwell, NASA Art Program

Walker went on to say that it was the artists’ job “…not only to record the physical appearance of the strange new world which space technology is creating, but to edit, select and probe for the inner meaning and emotional impact of events which may change the destiny of our race.”

And that’s what they did. Artists like Norman Rockwell, Andy Warhol, Peter Hurd, Annie Liebowitz, Robert Rauschenberg, and others, all took part in the program.

Artist Peter Hurd painted the launch of Skylab in 1973. Image Credit: Peter Hurd, Courtesy of National Air and Space Museum, Smithsonian Institution
Artist Peter Hurd painted the launch of Skylab in 1973. Image Credit: Peter Hurd, Courtesy of National Air and Space Museum, Smithsonian Institution

In the 1970’s, thinkers like Gerard K. O’Neill began to formulate ideas of what human colonies in space might look like. NASA held a series of conferences where these ideas were shared and explored. Artists Rick Guidice and Don Davis created many paintings and illustrations of what colony designs like Bernal Spheres, Double Cylinders, and Toroidal Colonies might look like.

This piece by artist Don Davis depicts the end-cap of a cylindrical colony. Notice the suspension bridge, and people enjoying themselves by a river. Image: Don Davis, NASA Ames Research Center
This piece by artist Don Davis depicts the end-cap of a cylindrical colony. Notice the suspension bridge, and people enjoying themselves by a river. Image: Don Davis, NASA Ames Research Center
This cut-away image of a Bernal Sphere colony was created by artist Rick Guidice. Image: Rick Guidice, NASA Ames Research Center
This cut-away image of a Bernal Sphere colony was created by artist Rick Guidice. Image: Rick Guidice, NASA Ames Research Center

NASA continues to work with artists, though the nature of the relationship has changed over the decades. Artists are often used to flesh out new discoveries when images are not available. Cassini’s so-called Grand Finale, when it will orbit between Saturn and its rings 22 times before crashing into the planet, was conceptualized by an unnamed artist.

An artist's illustration of the Cassini probe's Grand Finale. Image: NASA/JPL/CalTech
An artist’s illustration of the Cassini probe’s Grand Finale. Image: NASA/JPL/CalTech

The recent discovery of the exoplanets in the TRAPPIST-1 system was huge news. It still is. But TRAPPIST-1 is over 40 light years away, and NASA relied on artists to bring the discovery to life. This illustration was widely used to help us understand what planets orbiting the TRAPPIST-1 Red Dwarf might look like.

Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Credits: NASA/JPL-Caltech
Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Credits: NASA/JPL-Caltech

NASA now has quite a history of relying on art to convey what words can’t do. Space colonies, distant solar systems, and spacecraft ending their missions on other worlds, have all relied on the work of artists. But if I had to choose a favorite, it would probably be the 1981 water color by artist Henry Casselli. It makes you wonder what it’s like for an individual to take part in these species-defining endeavours. Just one person, sitting, contemplating, and preparing.

This Henry Casselli watercolor shows astronaut John Young preparing for a launch on April 12, 1981. What must he have been thinking as he prepared for the first flight of the Space Shuttle Program? Image: Henry Casselli, Courtesy NASA Art Program
This Henry Casselli watercolor shows astronaut John Young preparing for a launch on April 12, 1981. What must he have been thinking as he prepared for the first flight of the Space Shuttle Program? Image: Henry Casselli, Courtesy NASA Art Program

CERN Declares War On The Standard Model

The LHCb collaboration was launched in 2016 to test explore the events that followed the Big Bang. Credit: CERN

Ever since the discovery of the Higgs Boson in 2012, the Large Hadron Collider has been dedicated to searching for the existence of physics that go beyond the Standard Model. To this end, the Large Hadron Collider beauty experiment (LHCb) was established in 1995, specifically for the purpose of exploring what happened after the Big Bang that allowed matter to survive and create the Universe as we know it.

Since that time, the LHCb has been doing some rather amazing things. This includes discovering five new particles, uncovering evidence of a new manifestation of matter-antimatter asymmetry, and (most recently) discovering unusual results when monitoring beta decay. These findings, which CERN announced in a recent press release, could be an indication of new physics that are not part of the Standard Model.

In this latest study, the LHCb collaboration team noted how the decay of B0 mesons resulted in the production of an excited kaon and a pair of electrons or muons. Muons, for the record, are subatomic particles that are 200 times more massive than electrons, but whose interactions are believed to be the same as those of electrons (as far as the Standard Model is concerned).

The LHCb collaboration team. Credit: lhcb-public.web.cern.ch

This is what is known as “lepton universality”, which not only predicts that electrons and muons behave the same, but should be produced with the same probability – with some constraints arising from their differences in mass. However, in testing the decay of B0 mesons, the team found that the decay process produced muons with less frequency. These results were collected during Run 1 of the LHC, which ran from 2009 to 2013.

The results of these decay tests were presented on Tuesday, April 18th, at a CERN seminar, where members of the LHCb collaboration team shared their latest findings. As they indicated during the course of the seminar, these findings are significant in that they appear to confirm results obtained by the LHCb team during previous decay studies.

This is certainly exciting news, as it hints at the possibility that new physics are being observed. With the confirmation of the Standard Model (made possible with the discovery of the Higgs boson in 2012), investigating theories that go beyond this (i.e. Supersymmetry) has been a major goal of the LHC. And with its upgrades completed in 2015, it has been one of the chief aims of Run 2 (which will last until 2018).

A typical LHCb event fully reconstructed. Particles identified as pions, kaon, etc. are shown in different colours. Credit: LHCb collaboration

Naturally, the LHCb team indicated that further studies will be needed before any conclusions can be drawn. For one, the discrepancy they noted between the creation of muons and electrons carries a low probability value (aka. p-value) of between 2.2. to 2.5 sigma. To put that in perspective, the first detection of the Higgs Boson occurred at a level of 5 sigma.

In addition, these results are inconsistent with previous measurements which indicated that there is indeed symmetry between electrons and muons. As a result, more decay tests will have to be conducted and more data collected before the LHCb collaboration team can say definitively whether this was a sign of new particles, or merely a statistical fluctuation in their data.

The results of this study will be soon released in a LHCb research paper. And for more information, check out the PDF version of the seminar.

Further Reading: CERN, LHCb

Cygnus Soars to Space on Atlas Carrying SS John Glenn on Course to Space Station

Orbital ATK’s seventh cargo delivery flight to the International Space Station -in tribute to John Glenn- launched at 11:11 a.m. EDT April 18, 2017, on a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. Credit: Ken Kremer/kenkremer.com
Orbital ATK’s seventh cargo delivery flight to the International Space Station -in tribute to John Glenn- launched at 11:11 a.m. EDT April 18, 2017, on a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – Orbital ATK’s Cygnus supply ship soared to space from the Florida Space Coast at lunchtime today, Tuesday, April 18, drenched in sunshine and carrying the ‘SS John Glenn’ loaded with over three and a half tons of precious cargo – bound for the multinational crew residing aboard the International Space Station (ISS).

Just like clockwork, Orbital ATK’s seventh cargo delivery flight to the station launched right on time at 11:11 a.m. EDT Tuesday at the opening of the launch window atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida.

The ‘SS John Glenn’ Cygnus resupply spacecraft was manufactured by NASA commercial cargo provider Orbital ATK. The vehicle is also known alternatively as the Cygnus OA-7 or CRS-7 mission.

“This was a great launch,” said Joel Montalbano, NASA’s deputy manager of the International Space Station program, at the post launch media briefing at NASA’s Kennedy Space Center.

‘We have a vehicle on its way to the ISS.”

Orbital ATK’s 7th cargo delivery flight to the International Space Station launched at 11:11 a.m. EDT April 18, 2017 carrying the SS John Glenn atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida, as seen from the VAB roof at KSC. Credit: Ken Kremer/kenkremer.com

Huge crowds gathered at public viewing areas ringing Cape Canaveral and offering spectacular views from Playalinda Beach to the north, the inland waterway and more beautiful space coast beaches to the south.

Near perfect weather conditions and extended views of the rocket roaring to orbit greeted all those lucky enough to be on hand for what amounts to a sentimental third journey to space for American icon John Glenn.

The launch was carried live on NASA TV with extended expert commentary. Indeed this launch coverage was the final one hosted by NASA commentator George Diller- the longtime and familiar ‘Voice of NASA’ – who is retiring from NASA on May 31.

The serene sky blue skies with calm winds and moderate temperatures were punctuated with wispy clouds making for a thrilling spectacle as the rocket accelerated northeast up the US East Coast on a carefully choreographed trajectory to the massive orbiting outpost.

“The status of the spacecraft is great!” said Frank Culbertson, a former shuttle and station astronaut and now Orbital ATK’s Space Systems Group president.

Liftoff of Orbital ATK SS John Glenn OA-7 mission atop ULA Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station, FL on April 18, 2017, as seen from VAB roof at KSC. Credit: Julian Leek

The mission is named the ‘S.S. John Glenn’ in tribute to legendary NASA astronaut John Glenn – the first American to orbit Earth back in February 1962.

Glenn was one of the original Mercury Seven astronauts selected by NASA. At age 77 he later flew a second mission to space aboard Space Shuttle Discovery- further cementing his status as a true American hero.

Glenn passed away in December 2016 at age 95. He also served four terms as a U.S. Senator from Ohio.

A picture of John Glenn in his shuttle flight suit and a few mementos are aboard.

After a four day orbital chase Cygnus will arrive in the vicinity of the station on Saturday, April 22.

“It will be captured at about 6 a.m. EDT Saturday,” Montalbano elaborated.

Expedition 51 astronauts Thomas Pesquet of ESA (European Space Agency) and Peggy Whitson of NASA will use the space station’s Canadian-built robotic arm to grapple Cygnus, about 6:05 a.m. Saturday.

They will use the arm to maneuver and berth the unmanned vehicle to the Node-1 Earth-facing nadir port on the Unity module.

Cygnus will remain at the space station for about 85 days until July before its destructive reentry into Earth’s atmosphere, disposing of several thousand pounds of trash.

The countdown for today’s launch of the 194-foot-tall two stage United Launch Alliance (ULA) rocket began when the rocket was activated around 3 a.m. The rocket was tested during a seven-hour long countdown.

This is the third Cygnus to launch on an Atlas V rocket from the Cape. The last one launched a year ago on March 24, 2016 during the OA-6 mission. The first one launched in December 2015 during the OA-4 mission. Each Cygnus is named after a deceased NASA astronaut.

“We’re building the bridge to history with these missions,” said Vernon Thorp, ULA’s program manager for Commercial Missions. “Every mission is fantastic and every mission is unique. At the end of the day every one of these missions is critical.”

“The Atlas V performed beautifully,” said Thorpe at the post launch briefing.

The other Cygnus spacecraft have launched on the Orbital ATK commercial Antares rocket from NASA Wallops Flight Facility on Virginia’s eastern shore.

Cygnus OA-7 is loaded with 3459 kg (7626 pounds) of science experiments and hardware, crew supplies, spare parts, gear and station hardware to the orbital laboratory in support over 250 research experiments being conducted on board by the Expedition 51 and 52 crews. The total volumetric capacity of Cygnus exceeds 27 cubic meters.

The official OA-7 payload manifest includes the following:

TOTAL PRESSURIZED CARGO WITH PACKAGING: 7,442.8 lbs. / 3,376 kg

• Science Investigations 2,072.3 lbs. / 940 kg
• Crew Supplies 2,103.2 lbs. / 954 kg
• Vehicle Hardware 2,678.6 lbs. / 1,215 kg
• Spacewalk Equipment 160.9 lbs. / 73 kg
• Computer Resources 4.4 lbs. / 2 kg
• Russian Hardware 39.7 lbs. / 18 kg

UNPRESSURIZED CARGO (CubeSats) 183 lbs. / 83 kg

The Orbital ATK Cygnus CRS-7 (OA-7) mission launched aboard an Atlas V Evolved Expendable Launch Vehicle (EELV) in the 401 configuration vehicle. This includes a 4-meter-diameter payload fairing in its longest, extra extended configuration (XEPF) to accommodate the enhanced, longer Cygnus variant being used.

“ULA is excited to be a part of the team that delivered such an important payload to astronauts aboard the ISS,” said Gary Wentz, ULA vice president of Human and Commercial Systems, in a statement.

“Not only are we delivering needed supplies as the first launch under our new RapidLaunch™ offering, but we are truly honored to launch a payload dedicated to John Glenn on an Atlas V, helping to signify the gap we plan to fill as we start launching astronauts from American soil again in 2018.”

The first stage of the Atlas V booster is powered by the RD AMROSS RD-180 engine. There are no side mounted solids on the first stage. The Centaur upper stage is powered by the Aerojet Rocketdyne RL10C-1 engine.

Overall this is the 71st launch of an Atlas V and the 36th utilizing the 401 configuration.

The 401 is thus the workhorse version of the Atlas V and accounts for half of all launches.

The Orbital ATK Cygnus spacecraft named for Sen. John Glenn, one of NASA’s original seven astronauts, stands inside the Payload Hazardous Servicing Facility at NASA’s Kennedy Space Center in Florida behind a sign commemorating Glenn on March 9, 2017. Launch slated for April 18 on a ULA Atlas V. Credit: Ken Kremer/Kenkremer.com

Watch for Ken’s onsite launch reports direct from the Kennedy Space Center in Florida.

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

Ken Kremer

Orbital ATK SS John Glenn CRS-7 launch vehicle with the Cygnus cargo spacecraft bolted to the top of the United Launch Alliance Atlas V rocket is poised for launch at Space Launch Complex 41 at Cape Canaveral Air Force Station on April 18, 2017. Credit: Ken Kremer/kenkremer.com

Ride Shotgun Through the Solar System with Chris Hadfield

A scene from 'Miniverse' where Chris Hadfield travels the solar system with a Tesla. Credit: CuriosityStream.

It sounds like a space nerd’s dream come true: riding in a Tesla with former astronaut Chris Hadfield, doing a science version of Carpool Karaoke. And to top it off, you’re driving through the Solar System.

A new film out called “Miniverse” via CuriosityStream takes you on a ride through a scaled-down version of our Solar System. It’s similar to other scaled solar system models — which make the huge distances in our cosmic neighborhood a little less abstract — like the Voyage Scale Model Solar System in Washington, DC, the Sagan Planet Walk in Ithaca, New York or the Delmar Loop Planet Walk in St. Louis, Missouri.

But this is bigger. In the Miniverse, various points across the continental United States indicate scaled distances between the planets.

Here’s the trailer:

The first leg of the trip takes viewers on a journey from the Sun all the way to Mars. In the scaled down solar system, that’s only the distance from Long Island to the other side of New York City. In the sky, Mars appears over the Freedom Tower in New York, and Jupiter towers above the Lincoln Memorial.

Then later, as distances between planets stretch out, the gas giants and ice giants spread across the mid-section of the US. Even our friend Pluto appears over the Pacific Ocean off the West Coast of California.

Astronaut Chris Hadfield and astronomer Laura Danly view Pluto from Santa Monica, California, in a scene from ‘Miniverse’. Credit: CuriosityStream.

Your traveling companions are pretty awesome.

Behind the wheel for the entire adventure is the funny and engaging Chris Hadfield. He’s joined by a distinguished band of interstellar hitchhikers: famed theoretical physicist Dr. Michio Kaku, as well as Derrick Pitts, Chief Astronomer at the Franklin Institute in Philadelphia, and Dr. Laura Danly, Curator of the Griffith Observatory in Los Angeles. Along the way, Hadfield poses questions to his guests about the various bodies in our solar system.

“The big takeaway is just how vast the distances are in the solar system,” Danly told Universe Today via email. “Every time we look at a drawing of our solar system it reinforces the wrong image in our minds. In reality, the planets are small and the distances are vast. Anyone who has driven cross-country knows that those miles get very long, day after day. So Miniverse provides a visceral feeling to just how great those distances are.”

A GPS-like view of the first leg of the trip through the Miniverse. Credit: CuriosityStream.

If you already have a CuriosityStream account, you can watch the film here. If you don’t, you can take advantage of a 30-day free trial in order to watch Miniverse, and all the other great science offerings available, such as Stephen Hawking’s Universe, Brian Cox’s Wonders of Life, and other topics from astronomy observing tips to info about various missions to theoretical physics. Check it out. If you’re interested in continuing after your free trial, the ad-free streaming service costs $2.99, $5.99 and $11.99 per month for standard definition, high definition, and ultra high definition 4K respectively.

We suggested to the CuriosityStream folks of putting physical markers along this path across the US, which would really make a great cross country road trip. Come along for the ride!

Ceres Prank Lands Bart Simpson In Detention For Eternity

Do you see Bart Simpson's face on these surface features on Ceres? Researchers studying the surface of the dwarf planet for evidence of the presence of ice do. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera
Do you see Bart Simpson's face on these surface features on Ceres? Researchers studying the surface of the dwarf planet for evidence of the presence of ice do. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera

Human-kind has a long history of looking up at the stars and seeing figures and faces. In fact, there’s a word for recognizing faces in natural objects: pareidolia. But this must be the first time someone has recognized Bart Simpson’s face on an object in space.

Researchers studying landslides on the dwarf planet Ceres noticed a pattern that resembles the cartoon character. The researchers, from the Georgia Institute of Technology, are studying massive landslides that occur on the surface of the icy dwarf. Their findings are reinforcing the idea that Ceres has significant quantities of frozen water.

Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera
Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera

In a new paper in the journal Nature Geoscience, the team of scientists, led by Georgia Tech Assistant Professor and Dawn Science Team Associate Britney Schmidt, examined the surface of Ceres looking for morphologies that resemble landslides here on Earth.

Research shows us that Ceres probably has a subsurface shell that is rich with water-ice. That shell is covered by a layer of silicates. Close examination of the type, and distribution, of landslides at different latitudes adds more evidence to the sub-surface ice theory.

Ceres is pretty big. At 945 km in diameter, it’s the largest object in the asteroid belt between Mars and Jupiter. It’s big enough to be rounded by its own gravity, and it actually comprises about one third of the mass of the entire asteroid belt.

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera
Type 1 landslides on Ceres are large and occur at higher latitudes. Image: Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera

The team used observations from the Dawn Framing Camera to identify three types of landslides on Ceres’ surface:

  • Type 1 are large, rounded features similar to glacier features in the Earth’s Arctic region. These are found mostly at high latitudes on Ceres, which is where most of the ice probably is.
  • Type 2 are the most common. They are thinner and longer than Type 1, and look like terrestrial avalanche deposits. They’re found mostly at mid-latitudes on Ceres. The researchers behind the study thought one of them looked like Bart Simpson’s face.
  • Type 3 occur mostly at low latitudes near Ceres’ equator. These are always found coming from large impact craters, and probably formed when impacts melted the sub-surface ice.
Type 3 landslides on Ceres occur at low latitudes at large craters, and form when ice is melted by impacts. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera
Type 3 landslides on Ceres occur at low latitudes at large craters, and form when ice is melted by impacts. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, taken by Dawn Framing Camera

The authors of the study say that finding larger landslides further away from the equator is significant, because that’s where most of the ice is.

“Landslides cover more area in the poles than at the equator, but most surface processes generally don’t care about latitude,” said Schmidt, a faculty member in the School of Earth and Atmospheric Sciences. “That’s one reason why we think it’s ice affecting the flow processes. There’s no other good way to explain why the poles have huge, thick landslides; mid-latitudes have a mixture of sheeted and thick landslides; and low latitudes have just a few.”  

Key to understanding these results is the fact that these types of processes have only been observed before on Earth and Mars. Earth, obviously, has water and ice in great abundance, and Mars has large quantities of sub-surface ice as well. “It’s just kind of fun that we see features on this small planet that remind us of those on the big planets, like Earth and Mars,” Schmidt said. “It seems more and more that Ceres is our innermost icy world.”

“These landslides offer us the opportunity to understand what’s happening in the upper few kilometers of Ceres,” said Georgia Tech Ph.D. student Heather Chilton, a co-author on the paper. “That’s a sweet spot between information about the upper meter or so provided by the GRaND (Gamma Ray and Neutron Detector) and VIR (Visible and Infrared Spectrometer) instrument data, and the tens of kilometers-deep structure elucidated by crater studies.”

It’s not just the presence of these landslides, but the frequency of them, that upholds the icy-mantle idea on Ceres. The study showed that 20% to 30% of craters on Ceres larger than 10 km have some type of landslide. The researchers say that upper layers of Ceres’ could be up to 50% ice by volume.

The Orbit of Neptune. How Long is a Year on Neptune?

Neptune from Voyager 2. Image credit: NASA/JPL

Here on Earth, a year lasts roughly 365.25 days, each of which lasts 24 hours long. During the course of a single year, our planet goes through some rather pronounced seasonal changes. This is the product of our orbital period, our rotational period, and our axial tilt. And when it comes to the other planets in our Solar System, much the same is true.

Consider Neptune. As the eight and farthest planet from the Sun, Neptune has an extremely wide orbit and a comparatively slow orbital velocity. As a result, a year on Neptune is very long, lasting the equivalent of almost 165 Earth years. Combined with its extreme axial tilt, this also means that Neptune experiences some rather extreme seasonal changes.

Orbital Period:

Neptune orbits our Sun at an average distance (semi-major axis) of 4,504.45 million km (2,798.656 million mi; 30.11 AU). Because of its orbital eccentricity (0.009456), this distance varies somewhat, ranging from 4,460 million km (2,771 million mi; 29.81 AU) at its closest (perihelion) to 4,540 million km (2,821 million mi; 30.33 AU) at its farthest (aphelion).

The orbit of Neptune and the other outer Solar planets, as well as the ice-rich Kuiper Belt that lies just beyond it. Credit: NASA

With an average orbital speed of 5.43 km/s, it takes Neptune 164.8 Earth years (60,182 Earth days) to complete a single orbital period. This means, in effect, that a year on Neptune lasts as long as about 165 years here on Earth. However, given its rotational period of 0.6713 Earth days (16 hours 6 minutes 36 seconds), a year on Neptune works out to 89,666 Neptunian solar days.

Given that Neptune was discovered in 1846, humanity has only known about its existence for 171 years (at the time of this article’s writing). That means that since its discovery, the planet has only completed a single orbital period (which ended in 2010) and is only seven years into its second. This orbital period will be complete by 2179.

Orbital Resonance:

Because of its location in the outer Solar System, Neptune’s orbit has a profound impact on the neighboring Kuiper Belt. This region, which is similar (but significantly larger) than the Main Asteroid Belt, consists of many small icy worlds and objects that extends from Neptune’s orbit (at 30 AU) to a distance of about 55 AU from the Sun.

Animated diagram showing the spacing of the Solar Systems planet’s, the unusually closely spaced orbits of six of the most distant KBOs, and the possible “Planet 9”. Credit: Caltech/nagualdesign

So much as Jupiter’s gravity has dominated the Asteroid Belt, affecting its structure and occasionally kicking asteroids and planetoids into the inner Solar System, Neptune’s gravity dominates the Kuiper Belt. This has led to the creation of gaps in the belt, empty regions where objects have achieved an orbital resonance with Neptune.

Within these gaps, objects have a 1:2, 2:3 or 3:4 resonance with Neptune, meaning they complete one orbit of the Sun for every two completed by Neptune, two for every three, or three for every four. The over 200 known objects that exist in the 2:3 resonance (the most populous) are known as plutinos, since Pluto is the largest of them.

Although Pluto crosses Neptune’s orbit on a regular basis, their 2:3 orbital resonance ensures they can never collide. On occasion, Neptune’s gravity also causes icy bodies to be kicked out of the Kuiper Belt. Many of these then travel to the Inner Solar System, where they become comets with extremely long orbital periods.

Neptune’s largest satellite, Triton, is believed to have once been a Kuiper Belt Object (KBO) – and Trans-Neptunian Object (TNO) – that was captured by Neptune’s gravity. This is evidenced by its retrograde motion, meaning it orbits the planet in the opposite direction as its other satellites. It also has a number of Trojan Objects occupying its L4 and L5 Lagrange points. These “Neptune Trojans” can be said to be in a stable 1:1 orbital resonance with Neptune.

Seasonal Change:

Much like the other planets of the Solar System, Neptune’s axis is tilted towards the Sun’s ecliptic. In Neptune’s case, it is tilted 28.32° relative to its orbit (whereas Earth is tilted at 23.5°). Because of this, Neptune undergoes seasonal change during the course of a year because one of its hemispheres will be receiving more sunlight than the other. But in Neptune’s case, a single season lasts a whopping 40 years, making it very hard to witness a full cycle.

While much of the heat that powers Neptune’s atmosphere comes from an internal source (which is currently unknown), a study conducted by researchers from Wisconsin-Madison University and NASA’s Jet Propulsion Laboratory revealed that seasonal change is also driven by solar radiation. This consisted of examining images of Neptune taken by the Hubble Space Telescope between 1996 and 2002.

These images revealed that Neptune’s massive southern cloud bands were becoming steadily wider and brighter over the six year period – which coincided with the southern hemisphere beginning its 40-year summer. This growing cloud cover was attributed to increased solar heating, as it appeared to be concentrated in the southern hemisphere and was rather limited at the equator.

Images taken by Hubble, showing seasonal change in its southern hemisphere. Credit: NASA, L. Sromovsky, and P. Fry (University of Wisconsin-Madison)

Neptune remains a planet of mystery in many ways. And yet, ongoing observations of the planet have revealed some familiar and comforting patterns. For instance, while it’s composition is vastly different and its orbit puts it much farther away from the Sun than Earth, its axial tilt and orbital period still result in its hemispheres experiencing seasonal changes.

It’s good to know that no matter how far we venture out into the Solar System, and no matter how different things may seem, there are still some things that stay the same!

We have written many articles about how long year is on the Solar planets here at Universe Today. Here’s The Orbit of the Planets. How Long Is A Year On The Other Planets?, The Orbit of Earth. How Long is a Year on Earth?, The Orbit of Mercury. How Long is a Year on Mercury?, The Orbit of Venus. How Long is a Year on Venus?,  The Orbit of Mars. How Long is a Year on Mars?, The Orbit of Jupiter. How Long is a Year on Jupiter?, The Orbit of Saturn. How Long is a Year on Saturn?, The Orbit of Uranus. How Long is a Year on Uranus?, The Orbit of Pluto. How Long is a Year on Pluto?

If you’d like more information on Neptune, take a look at Hubblesite’s News Releases about Neptune, and here’s a link to NASA’s Solar System Exploration Guide to Neptune.

We have recorded an entire episode of Astronomy Cast just about Neptune. You can listen to it here, Episode 63: Neptune.

Sources:

Do I Believe in UFOs?

Do I Believe In Aliens?

Whenever I do a new livestream on Instagram (hint hint, @universetoday on Instagram), it’s generally with an audience that doesn’t have a lot of experience with my work here on Universe Today or YouTube.

They’re enthusiastic about space, but they haven’t been exposed to a lot of the modern ideas about astrobiology and the search for extraterrestrials. They have, however, seen a lot of TV and movies.

Continue reading “Do I Believe in UFOs?”

SS John Glenn Launching Science Stash to Space Station atop Atlas V April 18 – Watch Live and 360 Degree Video

Orbital ATK SS John Glenn CRS-7 launch vehicle with the Cygnus cargo spacecraft bolted to the top of the United Launch Alliance Atlas V rocket is poised for launch at Space Launch Complex 41 at Cape Canaveral Air Force Station on April 18, 2017. Credit: Ken Kremer/kenkremer.com

Orbital ATK SS John Glenn CRS-7 launch vehicle with the Cygnus cargo spacecraft bolted to the top of the United Launch Alliance Atlas V rocket is poised for launch at Space Launch Complex 41 at Cape Canaveral Air Force Station on April 18, 2017. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – The ‘SS John Glenn’ cargo freighter stands proudly poised for launch at pad 41 from the Florida Space Coast on Tuesday April 18, loaded with a stash of nearly 4 tons of science investigations and essential supplies atop a United Launch Alliance Atlas V rocket destined for the multinational crew aboard the International Space Station (ISS).

The lunchtime liftoff of the ‘SS John Glenn’ Cygnus resupply spacecraft manufactured by NASA commercial cargo provider Orbital ATK is slated for 11:11 a.m. EDT Tuesday, April 18 from Space Launch Complex 41 on Cape Canaveral Air Force Station, FL.

The US cargo ships provided by NASA suppliers Orbital ATK and SpaceX every few months act as NASA’s essential railroad to space. And they are vital to operating the station with a steady stream of new research experiments as well as essential hardware, spare parts, crew supplies, computer, maintenance and spacewalking equipment as well food, water, clothing, provisions and much more.

The launch window lasts 30 minutes and runs from 11:11-11:41 a.m. EDT April 18.

Excited spectators are gathering from near and far and Tuesday’s weather outlook is spectacular so far.

Orbital ATK OA-7/CRS-7 vehicle rolls out to pad 41 atop ULA Atlas V rocket for launch from Space Launch Complex 41 at Cape Canaveral Air Force Station on April 18, 2017. Credit: Julian Leek

Blastoff of the S.S. John Glenn on the OA-7 or CRS-7 flight counts as Orbital ATK’s seventh contracted commercial resupply services mission to the ISS for NASA.

The ‘S.S. John Glenn’ is named in honor of legendary NASA astronaut John Glenn – the first American to orbit Earth back in February 1962.

If you can’t attend in person, there are a few options to watch online.

NASA’s Atlas V/Cygnus CRS-7 launch coverage will be broadcast on NASA TV and the NASA launch blog beginning at 10 AM, Tuesday morning.

You can watch the launch live NASA TV at: http://www.nasa.gov/nasatv

A ULA webcast will be available starting at 10 a.m. at: www.ulalaunch.com

And for the first time ever you can also watch the launch live via a live 360 stream on the NASA Television YouTube channel. The 360 degree broadcast starts about 10 minutes prior to lift off at:

http://youtube.com/nasatelevision

The late morning daytime launch offers the perfect opportunity to debut this technology with the rocket magnificently visible atop a climbing plume of smoke and ash – and with a “pads-eye” view!

NASA/ULA Atlas V launch of Orbital ATK SS John Glenn Cygnus spacecraft on OA-7 resupply ship on April 18, 2017. Credit: ULA/Orbital ATK/NASA

Science plays a big role in this mission in tribute named in tribute to John Glenn. Over one third of the payload loaded aboard Cygnus involves science.

“The new experiments will include an antibody investigation that could increase the effectiveness of chemotherapy drugs for cancer treatment and an advanced plant habitat for studying plant physiology and growth of fresh food in space,” according to NASA.

The astronauts will grow food in space, including Arabidopsis and dwarf wheat, in an experiment that could lead to providing nutrition to astronauts on a deep space journey to Mars.

“Another new investigation bound for the U.S. National Laboratory will look at using magnetized cells and tools to make it easier to handle cells and cultures, and improve the reproducibility of experiments. Cygnus also is carrying 38 CubeSats, including many built by university students from around the world as part of the QB50 program. The CubeSats are scheduled to deploy from either the spacecraft or space station in the coming months.”

Also aboard is the ‘Genes in Space-2’ experiment. A high school student experiment from Julian Rubinfien of Stuyvescent High School, New York City, to examine accelerated aging during space travel. This first experiment will test if telomere-like DNA can be amplified in space with a small box sized experiment that will be activated by station astronauts.

The Saffire III payload experiment will follow up on earlier missions to study the development and spread of fire and flames in the microgravity environment of space. The yard long experiment is located in the back of the Cygnus vehicle. It will be activated after Cygnus departs the station roughly 80 days after berthing. It will take a few hours to collect the data for transmission to Earth.

Furthermore you can learn more about the Orbital ATK CRS-7 mission by going to the mission home page at: http://www.nasa.gov/orbitalatk

Up close view of umbilical’s connecting to Atlas V rocket carrying Orbital ATK CRS-7 launch vehicle to the ISS at Space Launch Complex 41 at Cape Canaveral Air Force Station on April 17, 2017 prior to planned launch on April 18. Credit: Ken Kremer/kenkremer.com

From a weather standpoint, Tuesday’s launch outlook is outstanding at this time.

According to meteorologists with the U.S. Air Force 45th Weather Squadron we are forecasting a 90 percent chance of “go” conditions at the 11:11 a.m. EDT launch time. The primary concern is for the possibility of cumulus clouds.

The forecast calls for temperatures of 75-76° F with on-shore winds peaking below 10 knots during the countdown.

In the event of a delay for any reason related to weather or technical issues a backup launch opportunity exists for Wednesday, April 19, and also looks promising.

The AF is also predicting the same 90 percent chance of “go” conditions at launch time. With the primary concern again being for the possibility of cumulus clouds.

Orbital ATK SS John Glenn OA-7 vehicle atop ULA Atlas V rocket slated for launch from Space Launch Complex 41 at Cape Canaveral Air Force Station, FL on April 18, 2017. Credit: Julian Leek

The rocket was rolled out to pad 41 at about 9 a.m. EDT this morning Monday April 17, in a process that takes about 25 minutes

The rocket and spacecraft passed the Launch Readiness Review held by United Launch Alliance and Orbital ATK on April 15. Launch managers from ULA, Orbital ATK and NASA determined all is ready for Tuesday’s targeted launch to the ISS.

OA-7 is loaded with 3500 kg (7700 pounds) of science experiments and hardware, crew supplies, spare parts, gear and station hardware to the orbital laboratory in support over 250 research experiments being conducted on board by the Expedition 51 and 52 crews. The total volumetric capacity of Cygnus exceeds 27 cubic meters.

The Orbital ATK Cygnus spacecraft named for Sen. John Glenn, one of NASA’s original seven astronauts, stands inside the Payload Hazardous Servicing Facility at NASA’s Kennedy Space Center in Florida behind a sign commemorating Glenn on March 9, 2017. Launch slated for March 21 on a ULA Atlas V. Credit: Ken Kremer/Kenkremer.com

The Orbital ATK Cygnus CRS-7 (OA-7) mission will launch aboard an Atlas V Evolved Expendable Launch Vehicle (EELV) in the 401 configuration vehicle. This includes a 4-meter-diameter payload fairing in its longest, extra extended configuration (XEPF) to accommodate the enhanced, longer Cygnus variant being used.

Orbital ATK SS John Glenn Cygnus CRS-7 cargo ship bolted on top of United Launch Alliance Atlas V rocket is poised for launch to the ISS at Space Launch Complex 41 at Cape Canaveral Air Force Station on April 18, 2017. Credit: Ken Kremer/kenkremer.com

The first stage of the Atlas V booster is powered by the RD AMROSS RD-180 engine. There are no side mounted solids on the first stage. The Centaur upper stage is powered by the Aerojet Rocketdyne RL10C-1 engine.

Overall this is the 71st launch of an Atlas V and the 36th utilizing the 401 configuration.

The 401 is thus the workhorse version of the Atlas V and accounts for half of all launches.

Orbital ATK Cygnus OA-7 spacecraft named the SS John Glenn for Original 7 Mercury astronaut and Sen. John Glenn, undergoes processing inside the Payload Hazardous Servicing Facility at NASA’s Kennedy Space Center in Florida on March 9, 2017 for launch slated for March 21 on a ULA Atlas V. Credit: Ken Kremer/Kenkremer.com

Watch for Ken’s onsite launch reports direct from the Kennedy Space Center in Florida.

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

Ken Kremer

………….

Learn more about the SS John Glenn/ULA Atlas V launch to ISS, NASA missions and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:

Apr 18-19: “SS John Glenn/ULA Atlas V launch to ISS, SpaceX SES-10, EchoStar 23, CRS-10 launch to ISS, ULA Atlas SBIRS GEO 3 launch, GOES-R weather satellite launch, OSIRIS-Rex, SpaceX and Orbital ATK missions to the ISS, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

Orbital ATK SS John Glenn Cygnus CRS-7 cargo ship bolted on top of United Launch Alliance Atlas V rocket is poised for launch to the ISS at Space Launch Complex 41 at Cape Canaveral Air Force Station on April 18, 2017. Credit: Ken Kremer/kenkremer.com

The Orbit of Saturn. How Long is a Year on Saturn?

Saturn. Image credit: Hubble

Every planet in the Solar System takes a certain amount of time to complete a single orbit around the Sun. Here on Earth, this period lasts 365.25 days – a period that we refer to as a year. When it comes to the other planets, we use this measurement to characterize their orbital periods. And what we have found is that on many of these planets, depending on their distance from the Sun, a year can last a very long time!

Consider Saturn, which orbits the Sun at a distance of about 9.5 AU – i.e. nine and a half times the distance between the Earth and the Sun. Because of this, the speed with which it orbits the Sun is also considerably slower. As a result, a single year on Saturn lasts an average of about twenty-nine and a half years. And during that time, some interesting changes happen for the planet’s weather systems.

Orbital Period:

Saturn orbits the Sun at an average distance (semi-major axis) of 1.429 billion km (887.9 million mi; 9.5549 AU). Because its orbit is elliptical – with an eccentricity of 0.05555 – its distance from the Sun ranges from 1.35 billion km (838.8 million mi; 9.024 AU) at its closest (perihelion) to 1.509 billion km (937.6 million mi; 10.086 AU) at its farthest (aphelion).

A diagram showing the orbits of the outer Solar planets. Saturn’s orbit is represented in yellow Credit: NASA

With an average orbital speed of 9.69 km/s, it takes Saturn 29.457 Earth years (or 10,759 Earth days) to complete a single revolution around the Sun. In other words, a year on Saturn lasts about as long as 29.5 years here on Earth. However, Saturn also takes just over 10 and a half hours (10 hours 33 minutes) to rotate once on its axis. This means that a single year on Saturn lasts about 24,491 Saturnian solar days.

It is because of this that what we can see of Saturn’s rings from Earth changes over time. For part of its orbit, Saturn’s rings are seen at their widest point. But as it continues on its orbit around the Sun, the angle of Saturn’s rings decreases until they disappear entirely from our point of view. This is because we are seeing them edge-on. After a few more years, our angle improves and we can see the beautiful ring system again.

Orbital Inclination and Axial Tilt:

Another interesting thing about Saturn is the fact that its axis is tilted off the plane of the ecliptic. Essentially, its orbit is inclined 2.48° relative to the orbital plane of the Earth. Its axis is also tilted by 26.73° relative to the ecliptic of the Sun, which is similar to Earth’s 23.5° tilt. The result of this is that, like Earth, Saturn goes through seasonal changes during the course of its orbital period.

R. G. French (Wellesley College) et al., NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

Seasonal Changes:

For half of its orbit, Saturn’s northern hemisphere receives more of the Sun’s radiation than the southern hemisphere. For other half of its orbit, the situation is reversed, with the southern hemisphere receiving more sunlight than the northern hemisphere. This creates storm systems that dramatically change depending on which part of its orbit Saturn is in.

For staters, winds in the upper atmosphere can reach speeds of up to 5oo meters per second (1,600 feet per second) around the equatorial region. On occasion, Saturn’s atmosphere exhibits long-lived ovals, similar to what is commonly observed on Jupiter. Whereas Jupiter has the Great Red Spot, Saturn periodically has what’s known as the Great White Spot (aka. Great White Oval).

This unique but short-lived phenomenon occurs once every Saturnian year, around the time of the northern hemisphere’s summer solstice. These spots can be several thousands of kilometers wide, and have been observed on many occasions throughout the past – in 1876, 1903, 1933, 1960, and 1990.

Since 2010, a large band of white clouds called the Northern Electrostatic Disturbance have been observed, which was spotted by the Cassini space probe. Given the periodic nature of these storms, another one is expected to happen in 2020, coinciding with Saturn’s next summer in the northern hemisphere.

The huge storm churning through the atmosphere in Saturn’s northern hemisphere overtakes itself as it encircles the planet in this true-color view from NASA’s Cassini spacecraft. Image credit: NASA/JPL-Caltech/SSI

Similarly, seasonal changes affect the very large weather patterns that exist around Saturn’s northern and southern polar regions. At the north pole, Saturn experiences a hexagonal wave pattern which measures some 30,000 km (20,000 mi) in diameter, while each of it six sides measure about 13,800 km (8,600 mi). This persistent storm can reach speeds of about 322 km per hour (200 mph).

Thanks to images taken by the Cassini probe between 2012 and 2016, the storm appears to undergo changes in color (from a bluish haze to a golden-brown hue) that coincide with the approach of the summer solstice. This was attributed to an increase in the production of photochemical hazes in the atmosphere, which is due to increased exposure to sunlight.

Similarly, in the southern hemisphere, images acquired by the Hubble Space Telescope have indicated the existence of large jet stream. This storm resembles a hurricane from orbit, has a clearly defined eyewall, and can reach speeds of up to 550 km/h (~342 mph). And much like the northern hexagonal storm, the southern jet stream undergoes changes as a result of increased exposure to sunlight.

Saturn makes a beautifully striped ornament in this natural-color image, showing its north polar hexagon and central vortex (Credit: NASA/JPL-Caltech/Space Science Institute)

Cassini was able to captured images of the south polar region in 2007, which coincided with late fall in the southern hemisphere. At the time, the polar region was becoming increasingly “smoggy”, while the northern polar region was becoming increasingly clear. The reason for this, it was argued, was that decreases in sunlight led to the formation of methane aerosols and the creation of cloud cover.

From this, it has been surmised that the polar regions become increasingly obscured by methane clouds as their respective hemisphere approaches their winter solstice, and clearer as they approach their summer solstice. And the mid-latitudes certainly show their share of changes thanks to increases/decreases in exposure to solar radiation.

Much like the length of a single year, what we know about Saturn has a lot to do with its considerable distance from the Sun. In short, few missions have been able to study it in depth, and the length of a single year means it is difficult for a probe to witness all the seasonal changes the planet goes through. Still, what we have learned has been considerable, and also quite impressive!

We have written many articles about years on other planets here at Universe Today. Here’s The Orbit of the Planets. How Long Is A Year On The Other Planets?, The Orbit of Earth. How Long is a Year on Earth?, The Orbit of Mercury. How Long is a Year on Mercury?, The Orbit of Venus. How Long is a Year on Venus?,  The Orbit of Mars. How Long is a Year on Mars?, The Orbit of Jupiter. How Long is a Year on Jupiter?, The Orbit of Uranus. How Long is a Year on Uranus?, The Orbit of Neptune. How Long is a Year on Neptune?, The Orbit of Pluto. How Long is a Year on Pluto?

If you’d like more information on Saturn, check out Hubblesite’s News Releases about Saturn. And here’s a link to the homepage of NASA’s Cassini spacecraft, which is orbiting Saturn.

We have also recorded an entire episode of Astronomy Cast that’s just about Saturn. Listen here, Episode 59: Saturn.

Sources:

Could Space Travelers Melt As They Accelerate Through Deep Space?

Artist Mark Rademaker's concept for the IXS Enterprise, a theoretical interstellar spacecraft. Credit: Mark Rademaker/flickr.com

Forty years ago, Canadian physicist Bill Unruh made a surprising prediction regarding quantum field theory. Known as the Unruh effect, his theory predicted that an accelerating observer would be bathed in blackbody radiation, whereas an inertial observer would be exposed to none. What better way to mark the 40th anniversary of this theory than to consider how it could affect human beings attempting relativistic space travel?

Such was the intent behind a new study by a team of researchers from Sao Paulo, Brazil. In essence, they consider how the Unruh effect could be confirmed using a simple experiment that relies on existing technology. Not only would this experiment prove once and for all if the Unruh effect is real, it could also help us plan for the day when interstellar travel becomes a reality.

To put it in layman’s terms, Einstein’s Theory of Relativity states that time and space are dependent upon the inertial reference frame of the observer. Consistent with this is the theory that if an observer is traveling at a constant speed through empty vacuum, they will find that the temperature of said vacuum is absolute zero. But if they were to begin to accelerate, the temperature of the empty space would become hotter.

According to the theory of the Unruh effect, accelerating particles are subject to increased radiation. Credit: NASA/Sonoma State University/Aurore Simonnet

This is what William Unruh – a theorist from the University of British Columbia (UBC), Vancouver – asserted in 1976. According to his theory, an observer accelerating through space would be subject to a “thermal bath” – i.e. photons and other particles – which would intensify the more they accelerated. Unfortunately, no one has ever been able to measure this effect, since no spacecraft exists that can achieve the kind of speeds necessary.

For the sake of their study – which was recently published in the journal Physical Review Letters under the title “Virtual observation of the Unruh effect” – the research team proposed a simple experiment to test for the Unruh effect. Led by Gabriel Cozzella of the Institute of Theoretical Physics (IFT) at Sao Paulo State University, they claim that this experiment would settle the issue by measuring an already-understood electromagnetic phenomenon.

Essentially, they argue that it would be possible to detect the Unruh effect by measuring what is known as Larmor radiation. This refers to the electromagnetic energy that is radiated away from charged particles (such as electrons, protons or ions) when they accelerate. As they state in their study:

“A more promising strategy consists of seeking for fingerprints of the Unruh effect in the radiation emitted by accelerated charges. Accelerated charges should back react due to radiation emission, quivering accordingly. Such a quivering would be naturally interpreted by Rindler observers as a consequence of the charge interaction with the photons of the Unruh thermal bath.”

Diagram of the experiment to test the Unruh effect, where electrons are injected into a magnetic field and subjected to lateral and vertical pulls. Credit: Cozzella, Gabriel (et al.)

As they describe in their paper, this would consist of monitoring the light emitted by electrons within two separate reference frames. In the first, known as the “accelerating frame”, electrons are fired laterally across a magnetic field, which would cause the electrons to move in a circular pattern. In the second, the “laboratory frame”, a vertical field is applied to accelerate the electrons upwards, causing them to follow a corkscrew-like path.

In the accelerating frame, Cozzella and his colleagues assume that the electrons would encounter the “fog of photons”, where they both radiate and emit them. In the laboratory frame, the electrons would heat up once vertical acceleration was applied, causing them to show an excess of long-wavelength photons. However, this would be dependent on the “fog” existing in the accelerated frame to begin with.

In short, this experiment offers a simple test which could determine whether or not the Unruh effect exists, which is something that has been in dispute ever since it was proposed. One of the beauties of the proposed experiment is that it could be conducted using particle accelerators and electromagnets that are currently available.

On the other side of the debate are those who claim that the Unruh effect is due to a mathematical error made by Unruh and his colleagues. For those individuals, this experiment is useful because it would effectively debunk this theory. Regardless, Cozzella and his team are confident their proposed experiment will yield positive results.

Project Starshot, an initiative sponsored by the Breakthrough Foundation, is intended to be humanity’s first interstellar voyage. Credit: breakthroughinitiatives.org

“We have proposed a simple experiment where the presence of the Unruh thermal bath is codified in the Larmor radiation emitted from an accelerated charge,” they state. “Then, we carried out a straightforward classical-electrodynamics calculation (checked by a quantum-field-theory one) to confirm it by ourselves. Unless one challenges classical electrodynamics, our results must be virtually considered as an observation of the Unruh effect.”

If the experiments should prove successful, and the Unruh effect is proven to exist, it would certainly have consequences for any future deep-space missions that rely on advanced propulsion systems. Between Project Starshot, and any proposed mission that would involve sending a crew to another star system, the added effects of a “fog of photons” and a “thermal bath” will need to be factored in.

Further Reading: arXiv, ScienceMag