Beyond “Fermi’s Paradox” XII: What is the Waterworlds Hypothesis?

Artist's concept of Earth-like exoplanets, which (according to new research) need to strike the careful balance between water and landmass. Credit: NASA

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that the reason for the Great Silence is that many planets out there are just too watery!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, which includes the possibility that many exoplanets are Waterworlds, where water is so plentiful that life will be less likely to emerge and thrive.

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The Moon has Resources, but Not Enough to Go Around

A geological map of the Moon showing different formations and mineral deposits. Credit: NASA/GSFC/USGS

It’s no secret that in this decade, NASA and other space agencies will be taking us back to the Moon (to stay, this time!) The key to this plan is developing the necessary infrastructure to support a sustainable program of crewed exploration and research. The commercial space sector also hopes to create lunar tourism and lunar mining, extracting and selling some of the Moon’s vast resources on the open market.

Ah, but there’s a snag! According to an international team of scientists led by the Harvard & Smithsonian Center for Astrophysics (CfA), there may not be enough resources on the Moon to go around. Without some clear international policies and agreements in place to determine who can claim what and where, the Moon could quickly become overcrowded, overburdened, and stripped of its resources.

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RocketLab Recovers a First-Stage Booster for the First Time: “Return to Sender”

Credit: RocketLab

In recent years, one of the most impressive developments for space exploration has been the rise of the commercial space industry (aka. NewSpace). Beyond fulfilling contracts with space agencies like NASA to provide commercial and crewed launch services, private aerospace companies are also fostering innovation that is helping to reduce the cost of sending payloads to space.

Take RocketLab, the US/NZ-based small satellite launch company that has broken new ground with its Electron rocket. In a further bid to reduce the costs of individual launches, RocketLab announced last year that it would begin recovering and reusing the spent boosters of its rockets. Recently, the company took a big step by successfully retrieving the first stage of an Electron after it delivered a payload to orbit.

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At One Time, This Region of Mars was Inundated by a “Megaflood”

Thanks to multiple robotic missions that have explored Mars’ atmosphere, surface, and geology, scientists have concluded that Mars was once a much warmer, wetter place. In addition to having a thicker atmosphere, the planet was actually warm enough that flowing water could exist on the surface in the form of rivers, lakes, and even an ocean that covered much of the northern hemisphere.

According to new research based on data collected by NASA’s Curiosity mission, it appears that the Gale Crater (where the rover has been exploring for the past eight years) experienced massive flooding roughly 4 billion years ago. These findings indicate that the mid-latitudes of Mars were also covered in water at one time and offers additional hints that the region once supported life.

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Arecibo’s Damage is so Serious and Dangerous, They’re Just Going to Scrap the Observatory Entirely

The Arecibo Radio Telescope Credit: UCF

This past summer, the Arecibo Observatory suffered major damage when an auxiliary cable that supports the platform above the telescope broke and struck the reflector dish. Immediately thereafter, technicians with the observatory and the University of Central Florida (UCF) began working to stabilize the structure and assess the damage. Unfortunately, about two weeks ago (on Nov. 6th), a second cable broke causing even more damage.

Following a thorough review, the U.S. National Science Foundation (NSF) announced that the observatory cannot be stabilized without risking the lives of construction workers and staff at the facility. As such, after 57 years of faithful service and countless contributions to multiple fields of astronomy, the NSF has decided to commence plans for decommissioning the Arecibo Observatory.

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Scientists Have Re-Analyzed Their Data and Still See a Signal of Phosphine at Venus. Just Less of it

In September, an international team announced that based on data obtained by the Atacama Millimeter-submillimeter Array (ALMA) in Chile and the James Clerk Maxwell Telescope (JCMT) in Hawaii, they had discovered phosphine gas (PH3) in the atmosphere of Venus. The news was met with its fair share of skepticism and controversy since phosphine is considered a possible indication of life (aka. a biosignature).

Shortly thereafter, a series of papers were published that questioned the observations and conclusions, with one team going as far as to say there was “no phosphine” in Venus’ atmosphere at all. Luckily, after re-analyzing the ALMA data, the team responsible for the original discovery concluded that there is indeed phosphine in the cloud tops of Venus – just not as much as they initially thought.

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A 100-Meter Rotating Liquid Mirror Telescope on the Moon? Yes Please.

New results from the NASA/ESA Hubble Space Telescope suggest the formation of the first stars and galaxies in the early Universe took place sooner than previously thought. A European team of astronomers have found no evidence of the first generation of stars, known as Population III stars, when the Universe was less than one billion years old. This artist’s impression presents the early Universe. Image Credit: ESA/Hubble, M. Kornmesser.

In the coming years, some truly awesome next-generation telescopes are going to be gathering their first light. Between space telescopes like James Webb and Nancy Grace Roman, and ground-based telescopes like the Extremely Large Telescope (ELT) and the Giant Magellan Telescope (GMT), astronomers will be able to study aspects of the Universe that were previously inaccessible.

For instance, there are Population III stars, which are the first stars to have formed in the Universe. These stars are not observable in visible light and even next-generation facilities (like those mentioned above) will not be able to see them. But according to a team led by NASA Hubble Fellow Anna Schauer, the solution could be to build what she has named the “Ultimately Large Telescope” (ULT) on the Moon.

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Earth and the Moon Might Have Captured an Old Upper Stage Rocket

The crescent Earth rises above the lunar horizon in this spectacular photograph taken by the Apollo 17 crew in lunar orbit in December, 1972, during NASA’s final lunar landing mission in the Apollo program. Credit: NASA. Image editing and enhancement: Kevin Gill.

Back in September, the Pan-STARRS1 survey telescope noticed an object that followed a slight but distinctly curved path in the sky, a telltale sign that it was captured by Earth’s gravity. Initially, this object was thought to be a near-Earth Asteroid (NEA) and was given a standard designation by the Minor Planet Center (2020 SO). However, the Center for Near-Earth Object Studies (CNEOS) at NASA JPL had another theory.

Based on its orbit and the way solar radiation appeared to be pushing it off course, NASA scientists have since concluded that the object might actually be the spent upper stage booster of the Centaur rocket that launched the Surveyor 2 spacecraft towards the Moon in 1966. This finding could have implications for future surveys that pick up mysterious objects near Earth (‘Oumuamua occur).

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Past Supernovae Could be Written Into Tree Rings

A bubble of gas expanding at roughly 11 million miles per hour created by the shockwave from a supernova. Credit: NASA

When stars reach the end of their lifespan, they undergo gravitational collapse at their cores. The type of explosion that results is one of the most awesome astronomical events imaginable and (on rare occasions) can even be seen with the naked eye. The last time this occurred was in 1604 when a Type Ia supernova took place over 20,000 light-years away – commonly-known as Kepler’s Supernova (aka. SN1604)

Given the massive amounts of radiation they release, past supernovae are believed to have played a role in the evolution of our planet and terrestrial life. According to new research by CU Boulder geoscientist Robert Brakenridge, these same supernovae may have left traces in our planet’s biology and geology. These findings could have implications given fears that Betelgeuse might be on the verge of going supernova.

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New Horizons Saw the Universe With Even Less Light Pollution than Hubble’s View

Artist's impression of New Horizons' close encounter with the Pluto–Charon system. Credit: NASA/JHU APL/SwRI/Steve Gribben

In July of 2015, NASA’s New Horizons probe made history when it became the first mission ever to conduct a close flyby of Pluto. This was followed by the spacecraft making the first-ever encounter with a Kuiper Belt Object (KBO) – known as Arrokoth (aka. 2014 MU69) – on Dec.31st, 2018. In addition, its unique position in the outer Solar System has allowed astronomers to conduct rare and lucrative science operations.

This has included parallax measurements of Proxima Centauri and Wolf 359, the two closest stars to the Solar System. In addition, a team of astronomers led by the National Optical Astronomy Observatory (NOAO) and Southwest Research Institute (SwRI) used archival data from the probe’s Long Range Reconnaissance Imager (LORRI) to conduct measurements of the Cosmic Optical Background (COB).

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