Matt Williams, Author at Universe Today

July 29, 2020February 7, 2022 by Matt Williams

Beyond “Fermi’s Paradox” IV: What is the Rare Earth Hypothesis?

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 planets capable of supporting life are simply too rare.

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 high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Seventy years later, we still haven’t answered that question, which has led to many theories as to why the “Great Silence” endures. Today, we address another, which is the possibility that life-bearing planets like Earth are just very rare.

July 27, 2020July 27, 2020 by Matt Williams

According to Globular Clusters, the Universe is 13.35 Billion Years Old

This dazzling image shows the globular cluster Messier 69, or M 69 for short, as viewed through the NASA/ESA Hubble Space Telescope. Globular clusters are dense collections of old stars. In this picture, foreground stars look big and golden when set against the backdrop of the thousands of white, silvery stars that make up M 69. Another aspect of M 69 lends itself to the bejewelled metaphor: As globular clusters go, M 69 is one of the most metal-rich on record. In astronomy, the term “metal” has a specialised meaning: it refers to any element heavier than the two most common elements in our Universe, hydrogen and helium. The nuclear fusion that powers stars created all of the metallic elements in nature, from the calcium in our bones to the carbon in diamonds. Successive generations of stars have built up the metallic abundances we see today. Because the stars in globular clusters are ancient, their metallic abundances are much lower than more recently formed stars, such as the Sun. Studying the makeup of stars in globular clusters like M 69 has helped astronomers trace back the evolution of the cosmos. M 69 is located 29 700 light-years away in the constellation Sagittarius (the Archer). The famed French comet hunter Charles Messier added M 69 to his catalogue in 1780. It is also known as NGC 6637. The image is a combination of exposures taken in visible and near-infrared light by Hubble’s Advanced Camera for Surveys, and covers a field of view of approximately 3.4 by 3.4 arcminutes.

It is a widely-accepted theory today that when the first stars formed in our Universe (ca. over 13 billion years ago), they quickly came together to form globular clusters. These clusters then coalesced to others to form the first galaxies, which have been growing through mergers and evolving ever since. For this reason, astronomers have long-suspected that the oldest stars in the Universe are to be found in globular clusters.

The study of stars in these clusters is therefore a means of determining the age of the Universe, which is still subject to some guesswork. In this vein, an international team of astronomers and cosmologists recently conducted a study of globular clusters in order to infer the age of the Universe. Their results indicate that the Universe is about 13.35 billion years old, a result that could help astronomers learn more about the expansion of the cosmos.

July 27, 2020July 27, 2020 by Matt Williams

Astronauts Come Back to Earth on August 2nd, Completing the Full Crew Dragon Test

On Monday, March 30, 2020 at a SpaceX processing facility on Cape Canaveral Air Force Station in Florida, SpaceX successfully completed a fully integrated test of critical crew flight hardware ahead of Crew Dragon’s second demonstration mission to the International Space Station for NASA's Commercial Crew Program; the first flight test with astronauts onboard the spacecraft. NASA astronauts Bob Behnken and Doug Hurley participated in the test, which included flight suit leak checks, spacecraft sound verification, display panel and cargo bin inspections, seat hardware rotations, and more.

On May 30th, SpaceX and NASA made history when a Crew Dragon spacecraft carrying two astronauts (Robert Behnken and Douglas Hurley) launched atop a Falcon 9 rocket and rendezvoused with the International Space Station (ISS). With this one flight, NASA and SpaceX demonstrated that the US once again has domestic launch capability, something they have not enjoyed since the retirement of the Space Shuttle in 2011.

In one week, Sunday, August 2nd, Robert and Douglas will be returning to Earth using the same Crew Dragon spacecraft (named Endeavour) that took them to the ISS. This is the most crucial part of Demo-2 flight, where the spacecraft is tasked with bringing the astronauts home, safe and sound. As you can imagine, there are a lot of people who are understandably nervous, not the least of which is SpaceX founder Elon Musk.

July 24, 2020July 24, 2020 by Matt Williams

The Moon is an Ideal Spot for a Gravitational Wave Observatory

High-resolution view of the lunar surface (JAXA/SELENE)

In the coming years, multiple space agencies will be sending missions (including astronauts) to the Moon’s southern polar region to conduct vital research. In addition to scouting resources in the area (in preparation for the construction of a lunar base) these missions will also investigate the possibility of conducting various scientific investigations on the far side of the Moon.

However, two prominent scientists (Dr. Karan Jani and Prof. Abraham Loeb) recently published a paper where they argue that another kind of astronomy could be conducted on the far side of the Moon – Gravitational Wave astronomy! As part of NASA’s Project Artemis, they explain how a Gravitational-wave Lunar Observatory for Cosmology (GLOC) would be ideal for exploring GW in the richest and most challenging frequencies.

July 23, 2020February 7, 2022 by Matt Williams

Beyond “Fermi’s Paradox” III: What is the Great Filter?

The Karl Jansky Very Large Array at night, with the Milky Way visible in the sky. Credit: NRAO/AUI/NSF; J. Hellerman

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 there is something in the Universe that prevents life from reaching the point where we would be able to hear from it.

This became the basis of the Fermi Paradox, which refers to the high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Seventy years later, we still haven’t answered that question, which has led to many theories as to why the “Great Silence” endures. A popular one is that there must be “Great Filter” that prevents life from reaching an advanced stage of development.

July 23, 2020July 26, 2020 by Matt Williams

SpaceX Finally Catches Both Halves of a Falcon 9 Fairing

A Falcon 9 rocket lifting off from Cape Canaveral. Credit: SpaceX

On July 20th, SpaceX launched a South Korean military communications satellite (ANASIS-II) using the same Falcon 9 that delivered a pair of astronauts to the International Space Station (ISS) back in May. And in another interesting development, this mission was the first time that SpaceX managed to not only retrieve the first stage booster at sea but also retrieved both halves of the payload fairing.

July 21, 2020July 21, 2020 by Matt Williams

James Webb Completes a Comprehensive Systems Test for the First Time

Shown with its primary mirror fully deployed, NASA’s James Webb Space Telescope is the largest and most technically complex space science telescope NASA has ever built. Credit: NASA/Chris Gunn

In 1996, NASA began working on the James Webb Space Telescope (JWST), a next-generation infrared observatory that would be a total game-changer. And next year, after multiple delays, cost overruns, and exhaustive testing, the observatory will finally take to space. Despite an additional delay forced by the outbreak of COVID-19, NASA recently announced that it is targeting Oct. 31st, 2021, as the launch date.

In other good news, teams at NASA’s Goddard Space Flight Center took advantage of the fact that the JWST is now fully-assembled to conduct the highly-critical software and electrical analysis known as the Comprehensive Systems Test (CST). This was the first time that a full systems-evaluation was conducted on the fully-assembled vehicle, and will help ensure that the JWST will function in space when the time comes!

July 20, 2020July 20, 2020 by Matt Williams

Roman Space Telescope and SOFIA Get Their Funding Restored… Again

Artist's impression of the Nancy Grace Roman space telescope (formerly WFIRST). It could open a window on the early Universe by observing light from the first stars. Credit: NASA/GSFC — Artist's impression of the Nancy Grace Roman space telescope (formerly WFIRST). Credit: NASA/GSFC

In May of 2020, NASA made the decision to give the next-generation Wide Field Infrared Space Telescope (WFIRST) a proper name. Henceforth, it would be known as the Nancy Grace Roman Space Telescope (or Roman Space Telescope) in honor of NASA’s first Chief Astronomer and a woman’s who tireless work in the field of STEMs research led to the creation of the Hubble Space Telescope – hence her nickname, the “mother of Hubble”).

However, in recent months, the budget environment has not been too favorable to the Roman Space Telescope (RST), as well as education-related programs. But thanks to a recent bill considered by the House Appropriations Commitee, funding has been restored to five NASA science missions and projects – including the RST – that the administration’s budget proposal sought to cancel for the coming year.

July 18, 2020July 18, 2020 by Matt Williams

The Moon Might Have Formed a Little Later than Originally Believed

According to the Giant Impact Hypothesis, the Moon formed when a Mars-sized object (named Theia) collided with Earth billion years ago, at a time when the Earth was still a ball of magma. This event not only led to the Earth-Moon system we recognize today, it is also beleived to have led to the differentiation of the Earth’s core region into an molten Outer Core and a solid Inner Core.

However, there has been an ongoing debate as to the timing of this impact and how long the subsequent formation of the Moon took place. According to a new study by a team of German researchers, the Moon formed from a magma ocean that took up to 200 million years to solidify. This means that the Moon finished forming about 4.425 billion years ago, or 100 million years later than previously thought.

July 16, 2020July 21, 2020 by Matt Williams

Do the TRAPPIST-1 Planets Have Atmospheres?

Most exoplanets orbit red dwarf stars because they're the most plentiful stars. This is an artist's illustration of what the TRAPPIST-1 system might look like from a vantage point near planet TRAPPIST-1f (at right). Credits: NASA/JPL-Caltech

In February of 2017, the scientific community rejoiced as NASA announced that a nearby star (TRAPPIST-1) had a system of no less than seven rocky planets! Since that time, astronomers have conducted all kinds of follow-up observations and studies in the hopes of learning more about these exoplanets. In particular, they have been attempting to learn if any of the planets located in the stars Habitable Zone (HZ) could actually be habitable.

Many of these studies have been concerned with whether or not the TRAPPIST-1 planets have sufficient water on their surfaces. But just as important is the question of whether or not any have viable atmospheres. In a recent study that provides an overview of all observations to date on TRAPPIST-1 planets, a team found that depending on the planet in question, they are likely to have good atmospheres, if any at all.