NASA's New Horizons probe sent back a view of a Texas-sized ice sheet known as Sputnik Planitia. (Credit: NASA GSFC / SwRI / JHUAPL)
NASA’s New Horizons mission to Pluto has forced astronomers to rewrite their textbooks — but that’s not all: New Horizons also forced Les Johnson to rewrite a novel.
The space scientist was tasked with taking notes that the famed science-fiction writer and editor Ben Bova left behind when he died in 2020, and turning them into a novel set on Pluto to close out Bova’s Grand Tour series of solar system tales.
In the material that Bova had written for “Pluto,” he described a rocky world with just a little bit of ice on it. But when Johnson sent those notes to planetary scientist Alan Stern, the New Horizons mission’s principal investigator, had to set him straight.
“His first comment back to me was, ‘We never found anything on Pluto that was anything like that,'” Johnson says in the latest episode of the Fiction Science podcast. “And so I realized at that point that I was going to have to go back and revise the science behind the story of the environment on Pluto.”
The result is one of the first works of fiction that provides detailed descriptions of Pluto’s true surroundings, right down to the orange-tinged ice sheet of Sputnik Planitia and the dark and dirty spot on Charon, Pluto’s largest moon.
Images captured by the Canada-France-Hawaii Telescope between August and November 2011 zero in on 2017 OF201. (Credit: Cheng et al.)
Astrophysicists say they’ve identified an object beyond the orbit of Neptune that’s likely to qualify as a dwarf planet, alongside other trans-Neptunian objects including Pluto, the erstwhile “ninth planet.”
The discovery of 2017 OF201 touches upon another ninth-planet controversy: namely, whether there’s a large planet nicknamed Planet 9 or Planet X lurking somewhere on the edges of the solar system.
The heart-shaped region of Pluto's surface was formed at least in part by a cataclysmic "splat," scientists say. (Credit: NASA / JHUAPL / SwRI)
The most recognizable feature on Pluto is its “heart,” a relatively bright valentine-shaped area known as Tombaugh Regio. How that heart got started is one of the dwarf planet’s deepest mysteries — but now researchers say they’ve come up with the most likely scenario, involving a primordial collision with a planetary body that was a little more than 400 miles wide.
Astronomers from the University of Bern in Switzerland and the University of Arizona looked for computer simulations that produced dynamical results similar to what’s seen in data from NASA’s New Horizons probe. They found a set of simulations that made for a close match, but also ran counter to previous suggestions that Pluto harbors a deep subsurface ocean. They said their scenario doesn’t depend on the existence of a deep ocean — which could lead scientists to rewrite the history of Pluto’s geological evolution.
An artist's conception compares the size of 889-mile-wide
Makemake and 1,445-mile-wide Eris. (SWRI Illustration)
They may be dwarf planets, but they’re not dead planets.
NASA’s James Webb Space Telescope has provided scientists with evidence of geothermal activity deep within two far-out dwarf planets, Eris and Makemake.
“We see some interesting signs of hot times in cool places,” Christopher Glein, an expert in planetary geochemistry at the Southwest Research Institute, said this week in a news release. Glein is the lead author of a study analyzing the JWST findings that was recently published by the journal Icarus.
An artist's conception shows NASA's New Horizons probe and a Kuiper Belt object called Arrokoth. (Credit: JHUAPL / SwRI)
Nearly eight years after its historic Pluto flyby, NASA’s New Horizons probe is getting ready for another round of observations made from the icy edge of the solar system — and this time, its field of view will range from Uranus and Neptune to the cosmic background far beyond our galaxy.
Scientists on the New Horizons team shared their latest discoveries, and provided a preview of what’s ahead, during this week’s Lunar and Planetary Science Conference in The Woodlands, Texas.
It’s been 17 years since the piano-sized New Horizons spacecraft was launched toward Pluto and the Kuiper Belt, The primary mission hit its peak in 2015 when the probe zoomed past Pluto, but the adventure moved on to a second act that focused on a smaller, two-lobed object called Arrokoth — a name derived from the Powhatan/Algonquin word for “sky.”
Scientists are still sifting through the data from the Pluto flyby, and from the Arrokoth flyby on New Year’s Day of 2019, more than 4 billion miles from the sun.
A mosaic image from NASA's Dawn spacecraft uses false color to highlight the recently exposed brine, or salty liquids, that were pushed up from a deep reservoir under Ceres' crust. In this view of a region of Occator Crater, they appear reddish. (NASA / JPL-Caltech / UCLA / MPS / DLR / IDA)
For example, consider the bright spots in Ceres’ Occator Crater, which some have likened to “alien headlights.” The reflectivity is due to a crust of sodium carbonate, a salt left behind by the evaporation of briny water that percolated up to the surface.
Gravity readings gathered during the latter days of Dawn’s mission led scientists to conclude that the brine came from a reservoir that’s 25 miles deep and hundreds of miles wide.
In one of the bright spots, known as Cerealia Facula, Dawn’s instruments detected a concentration of hydrated salt compounds. The fact that those compounds are still hydrated suggest that they must have reached the surface relatively recently — perhaps within the past few centuries. That suggests that the transfer of liquid material from Ceres’ deep reservoir is continuing.
“For the large deposit at Cerealia Facula, the bulk of the salts were supplied from a slushy area just beneath the surface that was melted by the heat of the impact that formed the crater about 20 million years ago,” Dawn principal investigator, Carol Raymond, explained in a news release. “The impact heat subsided after a few million years; however, the impact also created large fractures that could reach the deep, long-lived reservoir, allowing brine to continue percolating to the surface.”
Dawn’s scientists saw additional evidence for Ceres’ active, slush-based geology in the presence of conical hills reminiscent of earthly features known as pingos. On Earth, pingos are formed when pressurized groundwater freezes beneath the surface and pushes up the soil above. Similar geological structures have been observed on Mars.
On icy moons such as Europa, Enceladus and Titan, geological activity is primarily driven by gravitational interactions with their parent planets. The fact that Ceres is geologically active, even though its crust is not being flexed by a nearby planet, widens the possibilities for finding slush or liquid water deep within ice-rich worlds in the main asteroid belt, the Kuiper Belt and elsewhere.
The data-gathering phase of Dawn’s mission ended in 2018, and the dead spacecraft is now silently circling Ceres. But decades or centuries from now, the scientific findings resulting from the mission just might guide explorers to new kinds of interplanetary watering holes.
An artist’s conception shows the distant object known as 2018 VG18 or “Farout.” (Carnegie Institution for Science Illustration / Roberto Molar Candanosa)
Astronomers say they’ve discovered the most distant body ever observed in our solar system, a potential dwarf planet that’s about 11 billion miles from the sun.
Its nickname? “Farout.”
The far-out object — which is also known by its more official but less colorful designation, 2018 VG18 — was detected with Japan’s 8-meter Subaru Telescope in Hawaii during a campaign to look for extremely distant solar system objects, including a hypothetical Planet X or Planet Nine.
Further observations to confirm Farout’s distance and determine its brightness and color were made with the 6.5-meter Magellan Telescopes at the Carnegie Institution for Science’s Las Campanas Observatory in Chile. The observations were reported today in a circular distributed by the International Astronomical Union’s Minor Planet Center.
This photo of Ceres and the bright regions in Occator Crater was one of the last views NASA’s Dawn spacecraft transmitted before it completed its mission. This view, which faces south, was captured on Sept. 1 from an altitude of 2,340 miles as the spacecraft was ascending in its elliptical orbit. (NASA / JPL-Caltech / UCLA / MPS / DLR / IDA Photo)
Dawn is dead, but Dawn is not gone: Today NASA said that the Dawn spacecraft has fallen out of contact with Earth, presumably because it’s run out of the thruster fuel that was used to keep its antennas oriented toward Earth and its power-generating solar panels oriented toward the sun.
After Dawn missed out on communications sessions on Wednesday and today, NASA declared an end to the mission.
During its 11 years in space, Dawn sent back unprecedented closeups of the asteroid Vesta as well as Ceres, which is the largest known asteroid and the smallest confirmed dwarf planet.
Dawn will continue circling Ceres for decades to come in the main asteroid belt, 257 million miles out from the sun.
The International Space Station leaves a streak above the Subaru Telescope in a long-exposure image. Observations using the Subaru Telescope led to the discovery of the mini-world known as The Goblin. (Subaru Telescope / NAOJ Photo / Hideaki Fujiwara)
While searching for a hypothetical Planet Nine, astronomers found a distant mini-world that’s been given a spooky nickname: “The Goblin.”
The icy object was found at a distance of about 80 astronomical units from the sun, which translates to 7.4 billion miles. (One astronomical unit, or AU, equals 93 million miles, which is the distance between Earth and the sun.) That’s more than twice as far away as dwarf planet Pluto.
A research team led by Scott Sheppard of the Carnegie Institution of Science first spotted The Goblin just before Halloween in 2015. That timing, plus the fact that it was given the numerical designation 2015 TG387, gave rise to the trick-or-treat nickname. (T.G. … Get it?)
A composite image from NASA’s New Horizons spacecraft shows enhanced-color views of Pluto at lower right and Charon, its largest moon, at upper left. (NASA / JHUAPL / SwRI Photo)
Twelve years after the International Astronomical Union voted in a definition of planethood that reclassified Pluto, the debate goes on.
A newly published study uses the historical record to take aim at the definition’s most controversial clause: the idea that a planet in the solar system has to “clear the neighborhood of its orbit,” so that no other worlds are at a similar orbital distance.
