The extrasolar planet census recently passed a major milestone, with 5500 confirmed candidates in 4,243 solar systems. With so many exoplanets available for study, astronomers have learned a great deal about the types of planets that exist in our galaxy and have been rethinking several preconceived notions. These include the notion of “habitability” and whether Earth is the standard by which this should be measured – i.e., could there be “super habitable” exoplanets out there? – and the very concept of the circumsolar habitable zone (CHZ). Traditionally, astronomers have defined habitable zones based on the type of star and the orbital distance where a planet would be warm enough to maintain liquid water on its surface. But in recent years, other factors have been considered, including the presence of planetary magnetic fields and whether they get enough ultraviolet light. In a recent study, a team from Rice University extended the definition of a CHZ to include a star’s magnetic field. Their findings could have significant implications in the search for life on other planets (aka. astrobiology). The research team consisted of Anthony S. Atkinson, a graduate student with the Department of Physics and Astronomy at Rice University, Professor David Alexander, the director of the Rice Space Institute and member of the Texas Aerospace Research and Space Economy Consortium, and Alison O. Farrish, a NASA Postdoctoral Program Fellow at NASA’s Goddard Space Flight Center. The paper describing their findings, “Exploring the Effects of Stellar Magnetism on the Potential Habitability of Exoplanets,” appeared on July 9th in The Astrophysical Journal. Artist’s impression of exoplanets orbiting different types of stars. Credit: NASA/W. Stenzel On Earth, the presence of an intrinsic magnetic field has been vital to the emergence and evolution of life as we know it. Without it, our atmosphere would have been stripped away long ago by energetic particles emanating from the Sun – which was the case with Mars. In addition to Earth’s atmosphere, our planet’s magnetic field ensures that a limited amount of solar radiation and cosmic rays reach the surface. For this reason, astrobiologists consider a planetary magnetic field essential for determining whether or not an exoplanet is habitable. Another factor is how the strength of a planet’s magnetic field and its interaction with its parent star’s magnetic field affect habitability. Not only does an exoplanet require a strong field to shield it against stellar activity (solar flares, etc.), but it must also orbit far enough to avoid a direct magnetic connection with its star. “The fascination with exoplanets stems from our desire to understand our own planet better,” said Prof. Alexander in a recent Rice University press statement. “Questions about the Earth’s formation and habitability are the key drivers behind our study of these distant worlds.” The magnetic interactions between planets and their parent stars are known as “space weather.” For their study, the team examined 1,546 exoplanets to determine if they orbited inside or outside their host star’s Alfvén radius – the distance where stellar wind decouples from the star. This consisted of characterizing the stars’ activity known using their Rossby number (Ro) – the ratio between a star’s rotational period to their convective turnover time. Planets orbiting within this radius would directly interact magnetically with the star’s corona, leading to significant atmospheric stripping, ruling them out as viable candidates for habitability. This phenomenon has been observed with TRAPPIST-1 and its system of seven exoplanets. After examining the exoplanets in their study, they found that only two planets met all the conditions for potential habitability. These were K2-3 d and Kepler-186 f, two Earth-sized exoplanets 144 and 579 light-years from Earth (respectively). Illustration of Kepler-186f, a possible Earth-like exoplanet that could be a host to life. Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle These planets orbit within their stars’ CHZ, lie outside their Alfvén radius, and have strong enough magnetic fields to protect them from stellar activity. “While these conditions are necessary for a planet to host life, they do not guarantee it,” said Atkinson. “Our work highlights the importance of considering a wide range of factors when searching for habitable planets.” These findings highlight the need for continuous observation when studying exoplanet systems and considering what factors have led to the emergence of life here on Earth. They are also indicative of current efforts among astronomers and astrobiologists to refine the definition of “Habitable Zone” and create a more nuanced understanding. In so doing, this research could help refine the search for extraterrestrial life by allowing scientists to further constrain where they should be looking. Further Reading: Rice University, The Astrophysical Journal The post Planetary Habitability Depends on its Star’s Magnetic Field appeared first on Universe Today.

When the James Webb Space Telescope was launched it came with a fanfare expecting amazing things, much like the Hubble Space Telescope. One of JWST’s most anticipated target was TRAPPIST-1. This inconspicuous star is host to seven Earth-sized planets, with at least three in the habitable zone. The two inner planets are airless worlds but so far there has been no word of the third planet, the first in the habitable zone. The question is why and what makes it so tricky to observe? TRAPPIST-1 is a red dwarf star about 41 light years in the constellation Aquarius. The interest in the planets in the habitable zone is that the conditions could allow for the existence of liquid water. The seven planets were discovered through transit photometry where tiny drops in brightness of the star are observed due to the passage of the planets in front of the star.  The planets that orbit the star all have fairly short orbital periods from 1.5 days to 20 days. The result of this is that their transits across the stellar surface often overlap.  The launch of the JWST in 2021 reignited the interest in exoplanet studies. Its predecessor the Hubble Space Telescope was never expected to last as long to JWST was able to complement the famous telescope. Setting itself apart from Hubble by its advanced infrared capability, JWST was ideally placed to study exoplanet atmospheres. Fundamental to the operation of the JWST is a large, multi-segment mirror measuring 6.5 metres in diameter and a whole host of sophisticated instruments.  Artist impression of the James Webb Space Telescope A team of astronomers have been studying TRAPPIST-1 and its system of planets using JWST, exploiting its infrared capabilities. Using a technique known as transmission spectroscopy the starlight is explored as it passes through the planetary atmospheres as they pass in front of the star. Studying the light in this way can reveal the elements in the atmosphere. Three years in though and challenges have slowed them down.  Now, a paper published in Nature Astronomy highlights the challenges they faced and proposes how to overcome them. Top of the list relates to the non uniformity of a star. Those interested in solar astronomy will already be familiar with sun spots, flares and other solar phenomenon. These are seen on stars too and regions where cooler regions form can often harbour water vapour, playing havoc with transmission spectra and making it difficult to identify elements in the planetary atmosphere rather than in the star. This is known as stellar contamination.  Previous issues like this have been seen by astronomers studying exoplanet atmospheres using Earth based telescopes like the Magellan Telescope in Chile. Previously however, these issues were often simply ignored but the greater sensitivity of JWST causes more of a problem. There is a relatively simple work around however by observing the star as it rotates to build a picture of the stellar surface, allowing a more accurate analysis of the planetary atmosphere.  Magellan Telescope Using TRAPPIST-1 as a test bed, it is hoped that other challenges and their solutions can be tested before being applied to other, less easy to observe explanatory systems. The team propose that the exoplanet and JWST community work together on research projects to maximise efficiency in driving out solutions to other challenges in the road ahead.  Source : Roadmap details how to improve exoplanet exploration using the JWST The post Why is JWST Having So Much Trouble with the TRAPPIST-1 System? appeared first on Universe Today.

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Cops Faced Off With Feces Flinging Pro-Hamas Mob In Washington D.C. [VIDEOS]

The following article, HILARIOUS: The Speech Joe Biden Would Have Given If He Didn’t Have To Be Polite (Video), was first published on Conservative Firing Line. While everyone was waiting for him to duck his head out of Rehoboth and tell us if whether we still have six more months of Joe Biden, some meme guys let their imaginations run wild. Joe has said some pretty rough things on hot mics. Joe’s foul mouth and hot temper have been the subject … Continue reading HILARIOUS: The Speech Joe Biden Would Have Given If He Didn’t Have To Be Polite (Video) ...

An ode to empowerment. The post ‘I Will Survive’: How Gloria Gaynor’s classic empowerment anthem came to reflect the singer’s ongoing hardships first appeared on Far Out Magazine.

You will never believe it! Plus, update on Ozzy's health and any final show plans.