Scott Alan Johnston, Author at Universe Today

September 17, 2023September 17, 2023 by Scott Alan Johnston

A Collection of New Images Reveal X-Rays Across the Universe

NASA/CXC/SAO, JPL-Caltech, MSFC, STScI, ESA/CSA, SDSS, ESO.

One of the miracles of modern astronomy is the ability to ‘see’ wavelengths of light that human eyes can’t. Last week, astronomers put that superpower to good use and released five new images showcasing the universe in every wavelength from X-ray to infrared.

Combining data from both Earth- and ground-based telescopes, the five images reveal a diverse set of astronomical phenomena, including the galactic centre, the death throes of stars, and distant galaxies traversing the cosmos.

September 3, 2023September 3, 2023 by Scott Alan Johnston

A Bizarre Pulsar Switches Between Two Brightness Modes. Astronomers Finally Figured Out Why.

Pulsars are the lighthouses of the universe. These rotating dead stars shoot twin jets of radiation from their poles, usually with a predictable rhythm. But sometimes pulsars behave strangely, and one pulsar in particular has had astronomers scratching their heads for years. It’s called PSR J1023+0038, and a decade ago, it shut off its jets and began oscillating between two brightness levels in an unpredictable pattern. Now, scientists think they understand why: it is busy eating a neighboring star.

August 24, 2023August 24, 2023 by Scott Alan Johnston

IceCube-Gen2: 8 Cubic Kilometers of Ice, 5 Times the Sensitivity

The IceCube Neutrino Detector is an observatory unlike any other. Using sensors embedded inside a square kilometer chuck of Antarctic ice, it detects tiny particles called neutrinos, which rarely interact with ordinary matter and are incredibly hard to capture. IceCube has had several major successes in the last few years, including this summer’s announcement of a neutrino map of the Milky Way galaxy. But scientists are pushing up against the limits of IceCube’s capabilities, and plans are in the works for IceCube-Gen2: a detector 5 times as sensitive and 8 times as large, with a radio antenna array across four hundred square kilometers. IceCube Gen2 will increase the number of neutrino detections by an order of magnitude, and will be able to better pinpoint the sources from which the neutrinos are emitted.

August 6, 2023August 6, 2023 by Scott Alan Johnston

Two Stars Orbiting Each Other So Closely They Could Fit Inside the Sun

A brown dwarf: an object that weighs in somewhere between Jupiter and the least-massive known star. Credit: NASA/JPL-Caltech.

Astronomers have discovered a pair of star-like objects orbiting each other extremely quickly, with an entire ‘year’ lasting just 1.9 Earth hours. Catchily named ZTF J2020+5033, the system consists of one object which is definitely a small star, and another that straddles the boundary between star and planet. The two objects appear to be very old, and understanding how they came to be orbiting so close together is teaching astronomers more about how solar systems change and evolve.

August 5, 2023August 5, 2023 by Scott Alan Johnston

NASA Plans to Unleash a Wolf Pack of Rovers Onto the Lunar Surface in 2024

A pair of plastic prototypes of the CADRE rovers demonstrate driving in formation during a test at JPL last year. Credit: NASA/JPL-Caltech.

What’s better than one lunar rover? Three lunar rovers! In 2024, NASA plans to send a team of suitcase-sized wheeled robots to the Moon as part of the Commercial Lunar Payload Services (CLPS) program. Collectively called CADRE – Cooperative Autonomous Distributed Robotic Exploration – the rovers will spend one full lunar day (14 Earth days) exploring the Moon and showing off their unique capabilities.

July 21, 2023July 21, 2023 by Scott Alan Johnston

China is Working on a New Crew Spacecraft to Carry Up to 7 Passengers

China's Next Generation Spacecraft test vehicle after returning from orbit in 2020. China Central Television (CCTV).

China’s next-generation crew capsule was given an updated timeline this week. According to Yang Liwei, deputy chief designer of China’s Human Spaceflight Program, the new capsule will make its first flight in 2027 or 2028. Meeting this timeline will be a key milestone in China’s recently announced plan to land on the Moon by 2030.

July 4, 2023July 4, 2023 by Scott Alan Johnston

NASA's VIPER Rover's First Moments on the Moon Might Be its Most Terrifying

Volatiles Investigating Polar Exploration Rover (VIPER) Moon Gravitation Representative Unit 3 (MGRU3) Astrobotic Griffin Lunar Lander Structural Test Model (STM) egress testing. Credit: NASA/Dominic Hart.

NASA is building its first-ever robotic lunar rover. Named VIPER (Volatiles Investigating Polar Exploration Rover), the rover is set for launch in late 2024. But the terrain it will find when it reaches the Moon is impossible to predict. A series of tests carried out this spring are helping engineers understand the rover’s limits, and will ensure that VIPER can disembark from its lander even on extremely uneven terrain.

July 2, 2023July 2, 2023 by Scott Alan Johnston

NASA Locks Four Volunteers Into a One-Year Mission in a Simulated Mars Habitat

On June 25, 2023, a crew of four volunteers entered a simulated Martian habitat, from which they will not emerge for over a year. Their mission: to learn more about the logistics – and the human psychology – of living long-term on another planet, without ever leaving the ground.

June 24, 2023June 24, 2023 by Scott Alan Johnston

Early Black Holes Were Bigger Than We Thought

Every large galaxy in the nearby universe contains a supermassive black hole at its core. The mass of those black holes seems to have a relationship to the mass of the host galaxies themselves. But estimating the masses of more distant supermassive black holes is challenging. Astronomers extrapolate from what we know about nearby galaxies to estimate distant black hole masses, but it’s not a perfectly accurate measurement.

An astrophysicist at the University of Colorado, Boulder, Joseph Simon, recently proposed that there might be a better way to measure black hole mass, and his model indicates that early black holes may be much larger than other predictions suggest.

June 17, 2023June 17, 2023 by Scott Alan Johnston

We Could See the Glint off Giant Cities on Alien Worlds

How large would an extraterrestrial city have to be for current telescopes to see it? Would it need to be a planet-sized metropolis like Star Wars’ Coruscant? Or could we see an alien equivalent of Earth’s own largest urban areas, like New York City or Tokyo?

A recent preprint by Bhavesh Jaiswal of the Indian Institute of Science suggests that, in fact, we could see cities a mere fraction of that size, using a feature of light known as specular reflection.