A false-color mosaic Titan’s polar regions. Kraken Mare is the dim splotch to the right of center. Image: NASA/JPL-Caltech/University of Arizona/University of Idaho
Data gathered by NASA’s Cassini probe has allowed scientists to estimate the depth of Kraken Mare—the biggest methane sea on Saturn’s moon Titan.
New research published in the Journal of Geophysical Research is expanding our knowledge of Titan’s hydrocarbon seas, specifically Kraken Mare. This sea, approximately 600 miles (1,000 km) long, is larger than all five of North America’s Great Lakes combined and holds around 80% of the moon’s surface liquids. The seas on Titan contain lots of methane and ethane and are comparable to liquified natural gas on Earth.
Titan is the only moon in the solar system known to host an atmosphere. The thick, nitrogen-rich blanket that covers the moon hides a complex hydraulic system on the surface, but instead of liquid water, the rivers, lakes, and seas on Titan consist of oily black methane. Titan features other curiosities as well, such as gigantic dust storms, ice volcanoes, and enormous sand dunes.
As the new research shows, the deepest parts of Kraken Mare could be more than 1,000 feet (300 meters) deep. The team, led by Valerio Poggiali, a research associate at the Cornell Center for Astrophysics and Planetary Science, can’t actually be sure of that figure, because the radar pings used to determine sea depth never actually reached the seafloor.
False-color image of Kraken Mare. Image: NASA/JPL-Caltech/Agenzia Spaziale Italiana/USGS
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NASA’s Cassini spacecraft orbited Saturn from 2004 to 2017, and scientists have already studied some of the smaller seas on Titan using Cassini’s onboard altimeter. On August 21, 2014, Cassini flew to within 600 miles (970 km) of Titan’s surface and was able to send radar pings into Kraken Mare. Interestingly, this was the same flyby that resulted in the discovery of Ligeia Mare—a “magic” vanishing island on Titan.
Researchers at Cornell and NASA’s Jet Propulsion Laboratory devised a neat technique for determining the depth of Titan’s seas, which involves measuring differences between the time it takes radar to bounce back from the surface of the sea as opposed to the sea bottom. This technique helps to estimate sea depth, but the researchers have to make certain assumptions about the density of fluids on Titan and how quickly radio waves pass through them.
Using this technique, the team measured the depth of Moray Sinus, a northern estuary on Kraken Mare, which they found to be 280 feet (85 meters) deep. The absorption rate of the radar waves suggests the liquid in this part of the sea consists of 70% methane, 16% nitrogen, and 14% ethane. The scientists were expecting more methane than this due to the size and location of the sea, but this discovery suggests a more uniform distribution of chemicals across the moon’s various bodies of water.
Altimeter scans done across the main portion of Kraken Mare were less conclusive. As the authors write in the study, the NASA probe found “no evidence for signal returns from the sea floor, suggesting the liquid is either too deep or too absorptive for Cassini’s radio waves to penetrate.” That said, if the liquid in this part of the sea is similar in composition to the liquid found at Moray Sinus, then it must be deeper than 330 feet (100 meters) and possibly as deep as 1,000 feet (300 meters), according to the study.
Poggiali is hopeful that a robotic submarine might be sent to Titan one day to explore Kraken Mare or some other body of water. And in fact, he sees the new research as a step in that direction.
“Thanks to our measurements, scientists can now infer the density of the liquid with higher precision, and consequently better calibrate the sonar aboard the [future robotic submarine] and understand the sea’s directional flows,” explained Poggiali in a Cornell University statement.
A conceptual plan from 2015 showed how such a mission might look, but nothing has actually been approved in this regard. That said, NASA will be sending an aerial drone, called Dragonfly, to Titan, which should arrive at the moon at some point in the mid-2030s.
FILE PHOTO: SpaceX owner and Tesla CEO Elon Musk poses after arriving on the red carpet for the Axel Springer award, in Berlin, Germany, December 1, 2020. REUTERS/Hannibal Hanschke/Pool
(Reuters) – A veteran rocket from billionaire entrepreneur Elon Musk’s SpaceX aerospace company launched 143 spacecraft into space on Sunday, a new record for the most spaceships deployed on a single mission, according to the company.
The Falcon 9 rocket lifted off at 10 a.m. EST from the Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. It flew south along the eastern coast of Florida on its way to space, the company said.
The reusable rocket ferried 133 commercial and government spacecraft and 10 Starlink satellites to space – part of the company’s SmallSat Rideshare Program, which provides access to space for small satellite operators seeking a reliable, affordable ride to orbit, according to the company.
SpaceX delayed the launch one day because of unfavorable weather. On Jan. 22 Musk, also chief executive of Tesla Inc., wrote on Twitter: “Launching many small satellites for a wide range of customers tomorrow. Excited about offering low-cost access to orbit for small companies!”
SpaceX has previously launched to orbit more than 800 satellites of the several thousand needed to offer broadband internet globally, a $10 billion investment it estimates could generate $30 billion annually to help fund Musk’s interplanetary rocket program, called Starship.
Reporting by Helen Coster; Editing by Daniel Wallis
Artist’s impression of an Artemis mission to the Moon. Image: NASA
Despite the ongoing pandemic, there’s much to be excited about in space this year. NASA’s Perseverance rover is less than a month away from landing on Mars; the James Webb Space Telescope is scheduled to launch on Halloween; and the Space Launch System—NASA’s most powerful rocket ever—could see its inaugural launch later this year. And of course, there’s the Artemis program, which is supposed to deliver a woman and man to the lunar surface in just three years.
We will learn much in the coming weeks and months about President Biden’s NASA policy and what his administration believes is the best path forward for the American space program. In the meantime, we reached out to space experts, asking a very simple question: What should be Biden’s NASA priorities?
John Mogsdon, a professor or political science and international affairs from the Space Policy Institute at George Washington University, said: “I think it is important for President Biden and his administration to early on indicate a commitment to sustaining a human space exploration effort, with a return to the Moon as its first objective. The details of the current Artemis plan are likely to change, but it is well past time for the United States to once again be sending humans to distant destinations.”
Indeed, NASA is full-steam-ahead on the upcoming Artemis missions. The space agency originally planned for a lunar landing in 2028, but the Trump administration bumped that to 2024. It’s widely suspected that Biden will return NASA to its original timeline, but we can only speculate at this point.
Howard McCurdy, a professor of public affairs in the Department of Public Administration and Policy at American University in Washington, D.C., hopes that Biden keeps his eye on this prize—and other prizes to come. “His main space priority should be establishing a lunar/Mars exploration plan that lasts more than five years—also determining the future of the Boeing Starliner, launching the [James] Webb space telescope, and cementing the fate of the International Space Station,” said McCurdy. “He will have many science priorities, but NASA is not near the top of the list.”
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The whole Boeing Starliner thing is certainly worth a think, as this project—a spacecraft for delivering astronauts to the ISS—has been beset by problems and delays. The first crewed test of this system still appears to be a way’s off.
At the same time, SpaceX has delivered in the form the CrewDragon spacecraft, which successfully transported NASA astronauts Robert Behnken and Douglas Hurley to the ISS last year. McCurdy also brings up a good point about Mars, as the Artemis Moon program is a skipping stone for the first human journey to the Red Planet, which could happen in the 2030s.
Jessica West, a program officer at Project Ploughshares and the managing editor of its Space Security Index, had this to say: “The future of the Artemis program is essential. NASA’s international partners are going to want assurances and clarity on the scope of the U.S. commitment and timeline. Cooperation is key, both to succeed at space exploration and to ensure that our planet and humanity share in the benefits. This starts with diplomacy. NASA has drafted the Artemis Accords as a tool for the development of norms for space exploration. But it’s not clear how or if it will work with the wider international community to turn this into a more inclusive process, at a time when other states also have lunar ambitions.”
“The Biden Administration should also be sensitive to the effects that the Space Force–and it’s rhetorical emphasis on warfighting and domination–have on NASA and the global perceptions of it’s lunar ambitions,” West added.
West raises a very good point about the Artemis Accords. Humanity’s tendrils into space are growing longer and more numerous with each passing year, making things more complicated from a geopolitical perspective. It would be good to get buy-in from the international community on such matters, which may prove difficult with countries like Russia and China.
Peter Singer, a strategist at New America and author of Ghost Fleet and Burn-In, also chimed in about Space Force, the newest branch of the U.S. Armed Forces. “Trump created Space Command, mostly for the reason he saw it as an applause line at his rallies,” he said. “So how does NASA and this new military organization co-exist over the long term? They will need to work together when it makes sense, but to also ensure that we don’t risk the actual, or just appearance, of militarization of space in our civilian activities.”
Ah yes—the ongoing threat that we might militarize space. That’s tricky one, particularly as the U.S. tries to keep pace with its aggressive adversaries and as Space Force works to achieve “spacepower” in this prospective warfighting domain.
Moriba Jah, an aerospace engineer at the University of Texas, recommended the following: “The National Space Council—an organization that focuses and reports out on various national activities with regards to space, both in government, academia, and industry—should be allowed to continue under Biden. NASA has a footprint in the National Space Council, and that should be allowed to continue.”
Jah added: “There should be a dedicated emphasis in space safety and sustainability, including as it relates to space traffic management. In 2018, Trump signed Space Policy Directive-3 [which focused on space traffic management]. The former administration called on the Office of Space Commerce to take the lead role—and I’m good with that. As for NASA’s role, it should provide input and oversight to the government regarding the science and technology needs of space traffic management.”
Space traffic management will most certainly be an issue moving forward. As it stands, the rules surrounding what goes into space, and how much of it, are fairly loose. As of January 20, SpaceX has over 1,000 Starlink satellites in orbit, with plans to add thousands more. That satellites might crash into each other, creating large and dangerous clouds of debris, is a possibility that increases with each successive satellite added to low Earth orbit. We need someone to play traffic cop up there, as well as someone to take out the trash.
Dante Lauretta, principal investigator for the OSIRIS-REx mission and professor at the University of Arizona, hopes that the Biden Administration will maintain or increase funding for the NASA Science Mission Directorate. “This Directorate performs essential research to monitor and predict the effects of climate change, explore the Solar System, and survey the Universe,” he said. “Budgets over the past four years have been favorable, and this is one area of the U.S. federal government where science activities remain healthy. The amazing achievements of NASA science programs serve as shining examples of what we can do as a nation when we unite and focus on a common vision.”
Well said. It would be sad to squander all the good things NASA has going at the moment, including satellites to help us predict bad space weather and weather on Earth, surveys to monitor melting glaciers, and spacecraft careering into the Sun and interstellar space. And, per Lauretta’s interests, grabbing surface samples from a nearby asteroid.
Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, had plenty of sensible advice for President Biden: “NASA is the one part of the U.S. government that is not burning down right now, so don’t mess with (for the most part) success. What the human spaceflight program needs most is for the political leadership not to pull another 180, so continue Artemis despite its flaws, but remove the unrealistic 2024 deadline and appoint leaders who are not afraid to hold Boeing to account.”
McDowell also recommended firming up a plan for the end of the International Space Station, which has now been in orbit for more than 22 years and is showing its age. “Keep ISS going for a few more years to reap the investment made on CrewDragon and Starliner, but decide on the shutdown plan.”
“On the robotic/science side, fund it fully—supporting the climate science satellites and the education work the previous Administration tried to cut, get the Webb telescope into space and working, and let the science community pick the priorities going forward,” McDowell said. “Above all, don’t misuse the science program as a justification for the human space stuff—for example by forcing an emphasis on lunar-related science to provide a spurious justification for Artemis, which is the sort of thing that’s been done in the past.”
We also heard from Avi Loeb, an astronomy professor at Harvard University, whose recommendations were both philosophical and practical. “Given the wide interest in space exploration from the public, the scientific community and the commercial sector, it is essential to establish a new, bold vision that will maintain the leadership of the U.S. in space,” Loeb said. “This goes well beyond national security interests and relates back to JFK’s vision from 1962, the year I was born. The public is eager for inspiring initiatives, and space offers an ideal backdrop for an exciting vision that would advance our nation’s technological superiority. The importance of such a vision also builds on the immediate needs to add satellites that will allow better control of our effect on the climate and improve internet connectivity across the globe.”
Here, here. Space investment is often considered superfluous or indulgent, particularly as we face no shortage of problems on the surface. The challenge for Biden will be in achieving a fine balance—one that meets our needs here on Earth, while continuing to fulfill the legacy and potential of the American space program.