Distant Grind: The Sun Has 1.1 Billion Years Left to Sustain Life on Earth

The Sun produces energy through core thermonuclear fusion reactions which converts hydrogen into helium – for now. The Sun is becoming increasingly hotter (or more luminous) with time. However, the rate of change is so slight we won’t notice anything even over many millennia, let alone a single human lifetime. Eventually, however, the Sun will become[…]

Distant Grind: Does Outer Space End – or Go on Forever?

Astronomers know a lot about what’s in outer space – and think it’s possible it never ends. By Dr. Jack SingalAssociate Professor of PhysicsUniversity of Richmond Introduction Right above you is the sky – or as scientists would call it, the atmosphere. It extends about 20 miles (32 kilometers) above the Earth. Floating around the atmosphere[…]

Distant Grind: NASA Returning to Venus’s Hot Surface to Answer Some Questions

The missions will use radar and a probe to learn about Earth’s hard-to-study and potentially prophetic neighbor. By Dr. Paul K. ByrneAssociate Professor of Planetary ScienceNorth Carolina State University Introduction NASA is finally headed back to Venus. On June 2, 2021, NASA Administrator Bill Nelson announced that the agency had selected two winners of its latest[…]

Distant Grind: New Radio Bursts from across the Universe

Researchers just released data on more than 500 new bursts, quadrupling the total number of detected events. By Dr. Emmanuel FonsecaAssistant Professor of AstronomyWest Virginia University Introduction On June 9, 2021, my colleagues and I announced the discovery of 535 fast radio bursts that we detected using the Canadian Hydrogen Intensity Mapping Experiment telescope (CHIME). Detected in 2018 and[…]

Distant Grind: The Archaeoastronomy of Ancient Native American Chaco Culture

“As these people would view the heavens … there was an order of things up there.“ Curated/Reviewed by Matthew A. McIntoshPublic HistorianBrewminate Sun Dagger Two whorl-shaped etchings near the top of Fajada Butte compose the “Sun Dagger” petroglyph, tucked behind the eponymous rock panels of the “Three-Slab Site”. They are symbolically focal.[1][2] It consists of two spirals —[…]

Seven Ancient Cultures and How They Shaped Astronomy

With all their inventions and discoveries, it seems like the world connived to shape the astronomy of today. By Dr. Jason CookPlanetary AstronomerTelescopic Watch Introduction We as human beings are greatly attracted to beauty. And there is nothing more beautiful than the heavenly bodies set above us to see. From the stars, sun, moon, and[…]

Jesuit Influence on Post-Medieval Chinese Astronomy

Studies on ancient Chinese science suggest that up till the 14th century CE it was much more advanced than Europe in a technological sense. Introduction Ancient China had seen little Western contact before the 16th century CE, the language, culture and science all being allowed to develop independently of foreign influence. By the time European Jesuit missionaries arrived in[…]

The Uncertain Heavens: Christiaan Huygens’ Ideas of E.T. Life in the 1680s

During the 17th century, as knowledge of the Universe and its contents increased, so did speculation about life on other planets. This article, The Uncertain Heavens: Christiaan Huygens’ Ideas of Extraterrestrial Life, was originally published in The Public Domain Review under a Creative Commons Attribution-ShareAlike 3.0. If you wish to reuse it please see: https://publicdomainreview.org/legal/ The author[…]

Ancient Greek Astronomy and Cosmology

A brief tour of some of the astronomical ideas and models from ancient Greece. Introduction As the stars move across the sky each night people of the world have looked up and wondered about their place in the universe. Throughout history civilizations have developed unique systems for ordering and understanding the heavens. Babylonian and Egyptian[…]

Habitable Planets Could Exist around Pulsars

It is theoretically possible that habitable planets exist around pulsars – spinning neutron stars that emit short, quick pulses of radiation. According to new research, such planets must have an enormous atmosphere that converts the deadly x-rays and high energy particles of the pulsar into heat. The results, from astronomers at the University of Cambridge[…]

Dating the Sun’s Prenatal History Can Help Find Life on Other Planets

A new approach to dating the birth of our solar system could help find other similar systems. Flickr/Dmitry Boyarin, CC BY Without the sun, there would be no Earth – but amazingly, we don’t know the finer details about the prenatal history of our sun.    By Dr. Maria Lugaro (left) and Dr. Alexander Heger (right) / 08.08.2014[…]

How the Greeks Used Geometry to Understand the Stars

10th century CE Greek copy of Aristarchus of Samos’s calculations of the relative sizes of the sun, moon and the earth. / Konstable, Wikimedia Commons By Dr. Michael Fowler Maxine S. and Jesse W. Beams Professor of Physics , Physics Education,Theoretical Condensed Matter Physics University of Virginia Crystal Spheres: Plato, Eudoxus, Aristotle Plato, with his belief that the world[…]

Ancient Greek Astronomy: Measuring the Solar System

Eratosthenes teaching in Alexandria, by Bernardo Strozzi / Montreal Museum of Fine Arts via Wikimedia Commons The Greeks made the first real measurements of astronomical distances: the size of the earth and the distance to the moon, both determined quite accurately, and the distance to the sun, where their best estimate fell short by a factor of[…]

Star Wars and Medieval Manuscripts

By Dr. Bryan C. Keene / 12.14.2015 Adjunct Professor of Art History Pepperdine University As a certified Star Wars fan (thanks to my amazing father) *and* a curator of medieval manuscripts, I couldn’t resist putting together a guide of the out-of-this-world imagery and ideas about the universe from the Middle Ages. In medieval Europe there was a close link[…]

Ancients, Medievals, and Motion in the Heavens

Celestial map from 1670, by the Dutch cartographer Frederik de Wit / Wikimedia Commons By Dr. Michael Fowler / 07.23.2015 Maxine S. and Jesse W. Beams Professor of Physics , Physics Education,Theoretical Condensed Matter Physics University of Virginia Introduction The purpose of this lecture is just to review the various motions observed in the heavens in the simplest,[…]

Kindred Skies: Ancient Greeks and Aboriginal Australians Saw Constellations in Common

Yurri and Wanjel – the Gemini stars Castor and Pollux in the Wergaia traditions of western Victoria, Australia. Stellarium/John Morieson and Alex Cherney, CC BY-SA Many of the constellations we know in the night sky come from myths of the ancientGreeks. But similar stories are told by the oldest living cultures on Earth, including those of Australia. By Dr. Duane M. Hamacher /[…]

Goodbye Kepler, Hello TESS: New Satellite in the Search for Distant Planets

Imagined view from Kepler-10b, a planet that orbits one of the 150,000 stars that the Kepler spacecraft is monitoring. NASA/Kepler Mission/Dana Berry, CC BY When NASA first started planning the Kepler mission, no one knew if the universe held any planets outside our solar system. Thousands of exoplanets later, the search enters a new phase. By Dr. Jason Steffen / 04.09.2018 Assistant Professor of Physics and Astronomy[…]

How Eclipses were Regarded as Omens in the Ancient World

More than 2,000 years ago, the Babylonians understood the cycle of eclipses. They also regarded them as signs that could foretell the death of a king. By Dr. Gonzalo Rubio / 08.08.2017 Associate Professor of Classics and Ancient Mediterranean Studies Pennsylvania State University On Monday, August 21, people living in the continental United States will be able to see a total solar eclipse. Humans have been alternatively amused, puzzled,[…]

From the Pyramids to Stonehenge – Were Prehistoric People Astronomers?

Ricardo Liberato/wikimedia, CC BY-ND Understanding the past requires knowledge that goes beyond modern science. By Dr. Daniel Brown / 03.12.2018 Lecturer in Astronomy Nottingham Trent University Ever since humans could look up to see the sky, we have been amazed by its beauty and untold mysteries. Naturally then, astronomy is often described as the oldest of the sciences,[…]

Stephen Hawking: A Life of Success against All Odds

By Dr. Martin Rees / 03.14.2018 Emeritus Professor of Cosmology and Astrophysics University of Cambridge Soon after I enrolled as a graduate student at Cambridge University in 1964, I encountered a fellow student, two years ahead of me in his studies, who was unsteady on his feet and spoke with great difficulty. This was Stephen[…]

Why Physics Needs Art to Help Picture the Universe

Fig 1 By Dr. Frank Wilczek / 12.11.2015 Herman Feshbach Professor of Physics Massachusetts Institute of Technology Historians of science usually date the origin of the Scientific Revolution as 1543, when Copernicus’ De Revolutionibus first put the Earth in motion. While that is a convenient and defensible choice, it is not the only good candidate. An earlier[…]

Ancient Greece and the Origins of the Heliocentric Theory

Illuminated illustration of the Ptolemaic geocentric conception of the Universe by Portuguese cosmographer and cartographer Bartolomeu Velho (?-1568) / Wikimedia Commons      By (left-to-right) Dr. Milan S. Dimitrijevic, Dr. Efstratios Theodossiou, Aris Dacanalis, and Petros Z. Mantarakis Dimitrijevic: Research Professor, Astronomical Observatory Belgrade Theodossiou: Associate Professor of History and Philosophy of Astronomy and Physical Sciences, University of[…]

Most Distant and Youngest Supermassive Black Hole Discovered to Date

This artist’s concept shows the most distant supermassive black hole ever discovered. It is part of a quasar from just 690 million years after the Big Bang. / Robin Dienel/Carnegie Institution for Science 12.06.2017 Scientists have uncovered a rare relic from the early universe: the farthest known supermassive black hole. This matter-eating beast is 800 million[…]

Black Holes are Simpler than Forests and Science has Its Limits

Complex nature. Photo by Alan L/Flickr By Dr. Martin Rees / 12.01.2017 Emeritus Professor of Cosmology and Astrophysics University of Cambridge Albert Einstein said that the ‘most incomprehensible thing about the Universe is that it is comprehensible’. He was right to be astonished. Human brains evolved to be adaptable, but our underlying neural architecture has barely changed since[…]

Solar System’s First Observed Interstellar Visitor Dazzles Scientists

Artist’s concept of interstellar asteroid 1I/2017 U1 (‘Oumuamua) as it passed through the solar system after its discovery in October 2017. The aspect ratio of up to 10:1 is unlike that of any object seen in our own solar system. Credits: European Southern Observatory/M. Kornmesser 11.20.2017 Astronomers recently scrambled to observe an intriguing asteroid that zipped[…]

First Detection of Gravitational Waves and Light Produced by Colliding Neutron Stars

In a galaxy far away, two dead stars begin a final spiral into a massive collision. The resulting explosion unleashes a huge burst of energy, sending ripples across the very fabric of space. In the nuclear cauldron of the collision, atoms are ripped apart to form entirely new elements and scattered outward across the Universe.[…]

Incredible Photos of Jupiter from NASA’s Jupiter Probe

Image from NASA By Azriel ReShel / 11.09.2017 All photos credit NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt/Seán Doran Witness the Beauty of this Great Gas Giant NASA’s Juno probe has sent thrilling images of Jupiter back to Earth, the largest planet in the solar system. The fresh close-up images of Jupiter share unbelievable views of a hidden world. This is[…]