A comet with a nucleus 50 times larger than normal and 500 billion tons that travels in direction near Earth it was detected by NASA, where it was described as the largest ever seen by the scientific community. The astronomer from the University of Chile, Cesar Fuentestalked with CNN Chile regarding the scope of this discovery, assuring that it is a low-risk event for the planet. “This close is a relative term with respect to where this comet lives most of its time. It is extremely close to Earth, but for our scale very far“. The expert also explained that “the grace is that it is very large, much larger than other comets that we know.”
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Space
Climate change on Neptune? Temperatures are rising at the South Pole
written by Alexandra Hartman Editor-in-Chief
Astronomers from the European Southern Observatory have measured unexpected temperature changes on Neptune. Between 2003 and 2018, the global average temperature on the ice giant fell by eight degrees Celsius, writes a team led by Michael Roman from the University of Leicester and Glenn Orton from the Jet Propulsion Laboratory in the Planetary Science Journal. But at the South Pole itself, temperatures rose by 11 degrees Celsius between 2018 and 2020. These changes surprised the scientists.
Surprising rise in temperature at the South Pole
Of the planets in the solar system known to date, Neptune is the furthest out. It orbits the star at a distance of regarding 30 times that of Earth and is freezing cold: the atmosphere, which consists mainly of hydrogen, helium and methane, has an average temperature of -220 degrees Celsius. But like on Earth, temperatures fluctuate with the seasons. With the difference that a Neptune year, i.e. one orbit around the sun, lasts 165 Earth years.
It has been summer in the southern hemisphere since 2005. A team of astronomers has been taking thermal images of the planet for the 17 years since, using the best telescopes on Earth. These show that the planet cooled by 2018. In the last two years, there has been a surprising jump in temperature at the South Pole. “Our data cover less than half of a Neptune season, so nobody expected to see big and rapid changes,” says co-author Glenn Orton.
Possible cause: solar cycle
So far, the researchers have no explanation for the sharp fluctuations. Fluctuations in stratospheric chemistry, random weather patterns or changes caused by the solar cycle are possible. This should now show further data that are to be collected in the coming years.
In addition to the Very Large Telescope (VLT) of the European Southern Observatory, the Subaru, Keck and Gemini South and North telescopes were also involved in the investigation. The researchers also used data from NASA’s Spitzer Space Telescope.
Provides features about the beginnings of the universe .. Scientists discover the oldest and most distant galaxy known
written by Alexandra Hartman Editor-in-Chief
Astronomers have discovered what may be the oldest and most distant galaxy ever observed, which formed almost shortly following the Big Bang that dates the beginning of the universe, and may have been teeming with the first generation of stars.
The researchers said Thursday that the galaxy, dubbed (HD1), dates back more than 300 million years following the Big Bang, which occurred 13.8 billion years ago.
Evidence indicates that (HD1) formed stars at an astonishing rate, perhaps regarding 100 new stars per year, or alternatively it contained what might be the largest known black hole, they said.
The researchers gathered their information from telescopes in Hawaii and Chile and the Orbiting Spitzer Space Telescope. They hope to obtain more explanations using the James Webb Space Telescope, which will be operational within months following it was launched by the US Aeronautics and Space Administration (NASA) in December.
“Observing information regarding HD1 is limited and other physical properties are still mysterious, including its shape, total mass and metallicity,” said astronomer Yuichi Harikan, lead author of the research detailing the discovery, which was published in the Astrophysical Journal. Metallicity refers to the proportion of substances other than hydrogen and helium that were present in the early universe.
“The difficulty is that this is almost the limit of the capabilities of current telescopes in terms of sensitivity and wavelength,” Harrikan added.
The researchers said that HD1, which is likely to have a mass 10 billion times greater than our sun, may have had first-generation stars. These so-called Group C stars are extremely massive, luminous, hot, short-lived and composed almost exclusively of hydrogen and helium.
NASA delays dress rehearsal due to pressurization issue
written by Alexandra Hartman Editor-in-Chief
In a statement most laconic, the American Space Agency explains that this delay is the consequence of a “ loss of ability to pressurize the launcher which makes it impossible to safely fill the tanks.
« Teams will now meet to determine next steps and establish an action plan “. Optimistically, NASA adds that operations might resume on Monday depending on the results of the investigation.
As a reminder, Artemis I is the first step in a series of missions which should allow humans to return to the Moon. The Agency uses its SLS (Space Launch System) launcher with an Orion capsule. For Artemis I no team member is present.