Matt Williams, Author at Universe Today

April 2, 2019April 2, 2019 by Matt Williams

Satellites Watched a Huge Fireball Explode Above the Bering Sea Late Last Year

NASA's MODIS instrument, aboard the Terra satellite, captured this true-color image showing the remnants of a meteor's passage, seen as a dark shadow cast on thick, white clouds on Dec. 18, 2018. Credit: NASA GSFC

When a meteor strike the Earth’s atmosphere, a magnificent (and potentially deadly) explosion is often the result. The term for this is “fireball” (or bolide), which is used to describe exceptionally bright meteor explosions that are bright enough to be seen over a very wide area. A well-known example of this is the Chelyabinsk meteor, a superbolide that exploded in the skies over a small Russian town in February of 2013.

On December 18th, 2018, another fireball appeared in the skies over Russia that exploded at an altitude of about 26 km (16 mi) above the Bering Sea. The resulting debris was observed by instruments aboard the NASA Terra Earth Observation System (EOS) satellite, which captured images of the remnants of the large meteor a few minutes after it exploded.

March 28, 2019March 28, 2019 by Matt Williams

SpaceX Releases a New Render of What the All-Steel Starship Will Look Like Returning to Earth

SpaceX's first detailed render of the Starship reentering Earth's atmosphere. Credit: SpaceX

The design for SpaceX’s Starship (aka. Big Falcon Rocket) is really starting to come together! Over the holidays, sections of the Starship Hopper (a miniature version of the Starship) were photographed being put together at the company’s South Texas Launch Site. By mid-January, the parts were fully-integrated, forming the body of the stainless-steel prototype that would test the spacecraft’s overall architecture.

What followed, earlier this month, were tests of the Starship’s hexagonal heat shields to determine if they would offer sufficient protection during re-entry. And now, in anticipation of the spacecraft’s eventual launch, SpaceX released an eye-popping new rendering of the Starship that shows what it would look like reentering Earth’s atmosphere.

March 27, 2019November 21, 2021 by Matt Williams

Maybe Self-Replicating Robot Probes are Destroying Each Other. That’s Why We Don’t See Them

SETI's Allen Telescope Array monitor the stars for signs of intelligent life (SETI.org)

During the 1940s, Hungarian-American scientist John von Neumann developed a mathematical theory for how machines could endlessly reproduce themselves. This work gave rise to the idea of “von Neumann probes“, a class of self-replicating interstellar probes (SRPs) that could be used to do everything from exploring the Universe to seeding it with life and intervening in species evolution.

Some have naturally suggested that this be a focus of SETI research, which would entail looking for signs of self-replicating spacecraft in our galaxy. But as is always the case with proposals like these, the Fermi Paradox eventually reasserts itself by asking the age-old question – “Where is everybody?” If there are alien civilizations out there, why haven’t we found any evidence of their SRPs?

March 25, 2019March 25, 2019 by Matt Williams

Asteroid Bennu has Already Thrown Material off into Space 11 Times Since OSIRIS-REx Arrived

This asteroid Bennu ejecting particles from its surface on January 19 was created by combining two images taken by the NavCam 1 imager onboard NASA’s OSIRIS-REx spacecraft. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

On Dec. 31st, NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) rendezvoused with the asteroid 101955 Bennu. As part of an asteroid sample-return mission, NASA hopes that material from this near-Earth Asteroid (NEA) will reveal things about the history of the Solar System, the formation of its planets, and the origins of life on Earth.

Since the spacecraft established orbit around the asteroid, it has witnessed some interesting phenomena. This includes the first-ever close-up observations of particle plumes erupting from an asteroid’s surface. Since that time, the mission team has kept an eye out for these eruptions, which has allowed them to witness a total of 11 “ejection events” since the spacecraft first arrived.

March 22, 2019March 22, 2019 by Matt Williams

Pulsar Seen Speeding Away From the Supernova That Created it

Observations using the Very Large Array (orange) reveal the needle-like trail of pulsar J0002+6216 outside the shell of its supernova remnant, shown in image from the Canadian Galactic Plane Survey. The pulsar escaped the remnant some 5,000 years after the supernova explosion. Credit: NRAO

When a star exhausts its nuclear fuel towards the end of its lifespan, it undergoes gravitational collapse and sheds its outer layers. This results in a magnificent explosion known as a supernova, which can lead to the creation of a black hole, a pulsar or a white dwarf. And despite decades of observation and research, there is still much scientists don’t know about this phenomena.

Luckily, ongoing observations and improved instruments are leading to all kinds of discoveries that offer chances for new insights. For instance, a team of astronomers with the National Radio Astronomy Observatory (NRAO) and NASA recently observed a “cannonball” pulsar speeding away from the supernova that is believed to have created it. This find is already providing insights into how pulsars can pick up speed from a supernova.

March 20, 2019March 20, 2019 by Matt Williams

LIGO Just Got a Big Upgrade, Will Begin Searching for Gravitational Waves Again on April 1st

The Laser Interferometer Gravitational-Wave Observatory is made up of two detectors, this one in Livingston, La., and one near Hanford, Wash. The detectors use giant arms in the shape of an "L" to measure tiny ripples in the fabric of the universe. Credit: Caltech/MIT/LIGO Lab

In February of 2016, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) made history by announcing the first-ever detection of gravitational waves (GWs). These ripples in the very fabric of the Universe, which are caused by black hole mergers or white dwarfs colliding, were first predicted by Einstein’s Theory of General Relativity roughly a century ago.

About a year ago, LIGO’s two facilities were taken offline so its detectors could undergo a series of hardware upgrades. With these upgrades now complete, LIGO recently announced that the observatory will be going back online on April 1st. At that point, its scientists are expecting that its increased sensitivity will allow for “almost daily” detections to take place.

March 19, 2019March 19, 2019 by Matt Williams

Six People Have Begun a 122-Day Simulated Mission on the Moon

Here, a surface exploration crew begins its investigation of a typical, small lava tunnel, to determine if it could serve as a natural shelter for the habitation modules of a Lunar Base. Credit: NASA's Johnson Space Center

July 20st, 2019, will mark the 50th anniversary of the historic Moon Landing, where astronauts Neil Armstrong and Buzz Aldrin set foot on the lunar surface for the first time. This accomplishment was the high point of the “Space Race” and has remained NASA’s crowning achievement in space. In the coming years, NASA will attempt to return to the Moon, where they will be joined by several other space agencies.

To prepare for these eventual missions, a group of cosmonauts recently commenced an isolation experiment that will simulate a long-term mission to the Moon. It’s called the SIRIUS-19 experiment, which began earlier today at 02:00 p.m. local time (04:00 a.m. PDT; 07:00 a.m. EDT) at the Russian Academy of Sciences’ Institute of Biomedical Problems (IBMP) in Moscow.

March 19, 2019March 19, 2019 by Matt Williams

Almost 13,000 Years Ago, a Comet Impact Set Everything on Fire

Geologic and paleontological evidence unearthed in southern Chile supports the theory that a major cosmic impact event occurred approximately 12,800 years ago. Credit: UCSB

Roughly 12,800 years ago, planet Earth went through a brief cold snap that was unrelated to any ice age. For years, there have been geologists that have argued that this period was caused by an airburst or meteor fragments (known as the Younger Dryas Impact Theory). This event is beleived to have caused widespread destruction and the demise of the Clovis culture in North American.

This theory has remained controversial since it was first proposed. However, an international team of scientists recently discovered geological evidence in South America that could settle the debate. As the latest indication of an impact that took place during the Younger Dryas Boundary (YDB) period, this crater indicates that the effects of this event may have been more widespread than previously thought.

March 16, 2019June 29, 2019 by Matt Williams

Which Habitable Zones are the Best to Actually Search for Life?

Artist's impression of the range of habitable zones for different types of stars. Credit: NASA/Kepler Mission/Dana Berry

Looking to the future, NASA and other space agencies have high hopes for the field of extra-solar planet research. In the past decade, the number of known exoplanets has reached just shy of 4000, and many more are expected to be found once next-generations telescopes are put into service. And with so many exoplanets to study, research goals have slowly shifted away from the process of discovery and towards characterization.

Unfortunately, scientists are still plagued by the fact that what we consider to be a “habitable zone” is subject to a lot of assumptions. Addressing this, an international team of researchers recently published a paper in which they indicated how future exoplanet surveys could look beyond Earth-analog examples as indications of habitability and adopt a more comprehensive approach.

March 15, 2019March 15, 2019 by Matt Williams

Progress for the Skylon. Europe agrees to continue working on the air-breathing SABRE engine

An artist's conception of Reaction Engines' Skylon spacecraft. Credit: Reaction Engines

When it comes to the future of space exploration, the name of the game is “save money”. To do this, space agencies and aerospace companies around the world are investing in things like reusable rockets, single-stage-to-orbit (SSTO) rockets, and reusable space planes. This last concept builds on the tradition established by the Space Shuttle and Buran spacecraft, two reusable vehicles designed to make space launches more affordable.

The one drawback of these spacecraft was the fact that it still took two rocket boosters and a huge external fuel tank to put them into orbit. This is where the Synergetic Air Breathing Rocket Engine (SABRE) comes into play. With the help of the European Space Agency (ESA) and the UK Space Agency (UKSA), this revolutionary hypersonic engine recently took a big step towards fruition.