Evan Gough, Author at Universe Today

February 4, 2025February 4, 2025 by Evan Gough

Gaia Was Right. It Did Find a Planet.

Artist's illustration. Gaia detected this candidate exoplanet, named Gaia-4b, with astrometry. Now, follow-up spectroscopy has confirmed its existence. It's about twelve times more massive than Jupiter and orbits the star called Gaia-4, around 244 light-years away. Image Credit: ESA/Gaia/DPAC/M. Marcussen

The ESA’s Gaia mission mapped the positions and velocities of stars with extreme precision by measuring about one billion stars multiple times. It created a massive 3D map of the Milky Way that will pay scientific dividends for years to come. Gaia is based on astrometry, the study of the positions and movements of celestial objects.

Gaia also tentatively detected some planets, and new radial velocity studies have now confirmed the existence of one of them. The planet is an important outlier in exoplanet science.

February 4, 2025February 4, 2025 by Evan Gough

How Far Away Could We Detect… Ourselves?

New research asks if an ETI with our current level of technology could detect our technosignatures, and from how far away. Image Credit: SETI Institute

Revelations from the past can seem quaint once we’ve been living with them for a generation or two. That’s true of the realization in the past that spawned SETI: the Search for Extraterrestrial Intelligence. Humanity realized that if we’re blasting radio signals out into the cosmos haphazardly, then other ETIs, if they exist, are probably doing the same.

It seems obvious now, but back then, it was a revelation. So, we set up our radio antennae and began scanning the skies.

February 3, 2025February 3, 2025 by Evan Gough

The Hubble Space Telescope is a Powerful Science Instrument Despite its Age

This is supernova SN 2022aajn as observed by the Hubble. It's the small blue dot near the center of the image. The space telescope is examining this SN and 99 other Type Ia SN to refine our understanding of standard candles. Image Credit: ESA/Hubble & NASA, R. J. Foley (UC Santa Cruz)

This Hubble image shows a supernova named SN 2022aajn in a distant galaxy about 600 million light-years away with the unwieldy name of WISEA J070815.11+210422.3. However, the obtuse yet scientifically descriptive names aren’t what’s important.

What’s important is that SN 2022aajn is a Type 1a supernova, also known as a standard candle, and this image is part of a critical effort in cosmology.

February 3, 2025February 3, 2025 by Evan Gough

SETI Researchers Double-Checked 1 Million Objects for Signs of Alien Signals

SETI is developing a new way to search for technosignatures and the first results are in. Sadly, no alien signals were detected. Image Credit: SETI

We can’t help ourselves but wonder about life elsewhere in the Universe. Any hint of a biosignature or even a faint, technosignature-like event wrests our attention away from our tumultuous daily affairs. In 1984, our wistful quest took concrete form as SETI, the Search for Extraterrestrial Intelligence.

Unfortunately, or maybe fortunately, SETI has turned up nothing. Recently, scientists used a powerful new data system to re-examine data from one million cosmic objects and still came up empty-handed. Did they learn anything from this attempt?

January 31, 2025January 31, 2025 by Evan Gough

Japanese Lander Looks Back at Earth as it Heads to the Moon

Who can get tired of looking at Earth? Not ispace, who had their Hakuto-R mission to the Moon capture this view of Earth. The image is centered on Point Nemo, the point on Earth furthest from land. Image Credit: ispace

The Hakuto-R 2 mission launched on January 15, 2025. It’s the successor to Hakuto-R, which launched in December 2022 but failed when it lost communications during its descent. Both missions carried rovers, and this image was captured by the rover Resilience as it travels toward the Moon.

January 31, 2025January 31, 2025 by Evan Gough

Star Formation Might Depend on Galactic Magnetic Fields

The Hubble captured this image of Arp 220, the aftermath of a galactic merger about 250 million light-years away. It's the brightest of the three galactic mergers closest to Earth. Astronomers studied Arp 220 with the Submillimeter Array (SMA) to determine the role magnetic fields play in the formation of stars. Image Credit: NASA/ESA/STScI/HST

A galactic merger is a chaotic event. When two massive structures like galaxies merge, their powerful gravitational forces wrench stars out of their usual orbits in a process called violent relaxation. In essence, the merging galaxies are evolving rapidly, and small perturbations can be amplified as the system moves toward a more stationary state.

Intuition suggests that this chaos should disrupt the galaxy, including its star formation, but new observations of the Arp 220 galaxy merger show that something else happens: the merger creates a massive magnetic field that traps gas and encourages more stars to form.

January 31, 2025January 31, 2025 by Evan Gough

A Super-Earth to Test the Limits of Habitability

This illustration shows the habitable zone around the star HD 20794 (in green) and the trajectory of the three planets in the system. One of the planets moves through both the optimistic and pessimistic habitable zones. Image © Gabriel Pérez Díaz, SMM (IAC)

Every exoplanet discovery is an opportunity to refine models of planet formation, solar system architecture, habitable zones, and habitability itself. Each new planet injects more data into the scientific endeavour to understand what’s going on and how things got this way. However, some planets have such unusual characteristics that they invite a deeper focus and intense follow-up observations.

That’s the case for one new exoplanet. It’s a super-Earth on an unusual orbit that’s giving astronomers an opportunity to test the ideas of habitability and optimistic and pessimistic habitable zones.

January 30, 2025January 30, 2025 by Evan Gough

How Hydrogen Kept Early Mars Warm

An artist's illustration of an ancient Mars, flush with oceans, clouds and life. Image Credit: Kevin Gill.

Mars haunts us as a vision of a planet gone wrong. It was once warm and wet, with rivers flowing across its surface and (potentially) simple life residing in its water bodies. Now it’s dry and freezing.

Could Earth suffer this fate? Are there innumerable other worlds throughout the Universe that were habitable for a period of time before becoming uninhabitable?

January 29, 2025January 29, 2025 by Evan Gough

These Bizarre Features on Mars are Caused by Carbon Dioxide Geysers

These strange-looking landscape features form at Mars' south pole in springtime. They're created when frozen carbon dioxide turns to gas in the rising temperatures. Image Credit: NASA/JPL-Caltech/University of Arizona

Though it’s a cold, dead planet, Mars still has its own natural beauty about it. This image shows us something we’ll never see on Earth.

January 29, 2025January 29, 2025 by Evan Gough

Communicating with Gravitational Waves

This illustration shows the merger of two black holes and the gravitational waves that ripple outward as the black holes spiral toward each other. Could black holes like these (which represent those detected by LIGO on Dec. 26, 2015) collide in the dusty disk around a quasar's supermassive black hole explain gravitational waves, too? Credit: LIGO/T. Pyle — This illustration shows the merger of two supermassive black holes and the gravitational waves that ripple outward as the black holes spiral toward each other. Image Credit: LIGO/T. Pyle

When astronomers detected the first long-predicted gravitational waves in 2015, it opened a whole new window into the Universe. Before that, astronomy depended on observations of light in all its wavelengths.

We also use light to communicate, mostly radio waves. Could we use gravitational waves to communicate?