A cosmic signal from the early universe could reveal what the first stars were like

Understanding how the universe transitioned from darkness to light with the formation of the first stars and galaxies marks a turning point in cosmic evolution, known as the Cosmic Dawn. However, even the most powerful telescopes cannot observe these first stars directly, making it one of the greatest challenges in astronomy to determine their properties.

New clues to understanding the loss of the water Mars hosted billions of years ago

Mars is now an extremely arid planet, with pressure and temperature conditions that prevent liquid water from existing on its surface. However, geological and mineralogical evidence points to the presence of large volumes of water in the distant past, in the form of rivers, lakes, and even oceans. Despite decades of research, one of the biggest mysteries in Mars’ history remains unsolved: what happened to all that water?

First images of the Sun’s poles: a major milestone in solar exploration

 The Solar Orbiter mission, developed by the European Space Agency (ESA), has captured the first-ever images of the Sun’s south pole, released this Wednesday and marking a milestone in solar exploration.

Until now, all known images of our star had been taken from the plane of the ecliptic—that is, from a perspective aligned with Earth’s orbit around the Sun. Thanks to Solar Orbiter—a space probe launched five years ago with the goal of offering an unprecedented view of the Sun—our star has now been observed for the first time from outside this plane.

Not all active galaxies are the same: infrared observations reveal two distinct families

Active galactic nuclei (AGN) are areas at the centre of certain galaxies where a supermassive black hole releases an enormous amount of energy by sucking in the matter around it. These nuclei can influence the evolution of entire galaxies through their ability to drag in chemical elements and generate powerful winds that affect the galactic environment. In addition, these objects are localised and hidden behind dense dust clouds, which makes it difficult to study them directly. 

Discovery of a giant planet around a tiny star challenges theories of planet formation

Planets are born from the material surrounding young stars, in what is known as a protoplanetary disk. If the dust and gas in this disk clump together and accumulate enough mass, they can give rise to giant planets. However, this process heavily depends on the star’s mass: the smaller the star, the less material is available to form large planets.

Mysterious cosmic object detected emitting radio and X-ray signals synchronously

A lightshouse in space that lights up for two minutes —with an intensity that challenges our understanding— and then remains dark for more than forty, repeating this pattern again and again, offers a fitting metaphor for the behavior of long-period radio transients (LPTs). These recently discovered astronomical sources, whose nature remains elusive, emit brief pulses of radio waves at regular intervals lasting minutes or even hours.

New clues on how planet formation can mask the real properties of their star

 According to the latest data from NASA’s Exoplanet Archive, over 5,800 exoplanets have been confirmed to date. Of these, only about 5% orbit stars with intermediate solar masses—that is, between 1.5 and 2.5 times the mass of the Sun. This low proportion may be largely due to the challenges involved in detecting planets around this type of star.