An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. As of 1 February 2023, there are 5,307 confirmed exoplanets in 3,910 planetary systems, with 853 systems having more than one planet. The James Webb Space Telescope (JWST) is expected to discover more exoplanets, and also much more about exoplanets, including composition, environmental conditions and potential for life.
In astronomy, Kepler's laws of planetary motion, published by Johannes Kepler between 1609 and 1619, describe the orbits of planets around the Sun. The laws modified the heliocentric theory of Nicolaus Copernicus, replacing its circular orbits and epicycles with elliptical trajectories, and explaining how planetary velocities vary. The three laws state that:
- The orbit of a planet is an ellipse with the Sun at one of the two foci.
- A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.
- The square of a planet's orbital period is proportional to the cube of the length of the semi-major axis of its orbit.
In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbital plane. It differs from orbital inclination. At an obliquity of 0 degrees, the two axes point in the same direction; that is, the rotational axis is perpendicular to the orbital plane.
Hellboy is a fictional superhero created by writer-artist Mike Mignola. The character first appeared in San Diego Comic-Con Comics #2, and has since appeared in various eponymous miniseries, one-shots and intercompany crossovers. The character has been adapted into three live-action feature films. Two starring Ron Perlman in 2004 and 2008 in the title role, and one in 2019 which starred David Harbour, as well as two straight-to-DVD animated films, and three video games – Asylum Seeker, The Science of Evil, and as a playable character in Injustice 2.
The Bureau for Paranormal Research and Defense is a fictional organization in the comic book work of Mike Mignola, founded by the United States and United Kingdom governments, charged with researching the occult, paranormal and supernatural, and defending against their dangers. The B.P.R.D. originally appeared in the Hellboy comics and has since been a major part of its expanded universe.
Mike Mignola is an American comic book artist and writer best known for creating Hellboy for Dark Horse Comics, part of a shared universe of titles including B.P.R.D., Abe Sapien, Lobster Johnson, and various spin-offs. He has also created other supernatural and paranormal themed titles for Dark Horse including Baltimore, Joe Golem, and The Amazing Screw-On Head.
The Ogdru Jahad are fictional supervillains in Mike Mignola's Hellboy comic series. They are the Dragon of Revelation, and are destined to end the world. Though the Ogdru Jahad are the central antagonists of the franchise, they are not active. Their release from imprisonment instead being the object of many other villains' plans, namely Mad Monk Grigori Rasputin and the Neo-Nazi Thule Society and former Merlinean sorceress turned evil Nimue, the Blood Queen. They were imprisoned in their Golden Cocoons by the Right Hand of Doom shortly after the creation of Earth, but not before they spawned 369 children, known as the Ogdru Hem.
Katherine Corrigan is a fictional character from the Hellboy and B.P.R.D. comic book series published by Dark Horse Comics and created by Mike Mignola. Her appearance is based on Mignola's wife, Christine. Within the world of the comics, dubbed the "Mignola-verse", Corrigan acts as B.P.R.D. field leader to "enhanced" agents including Hellboy, Abe Sapien, Roger the Homunculus, Liz Sherman and Johann Kraus.
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of Montana, North Dakota, South Dakota, and Wyoming. In Montana, the Hell Creek Formation overlies the Fox Hills Formation. The site of Pompeys Pillar National Monument is a small isolated section of the Hell Creek Formation. In 1966, the Hell Creek Fossil Area was designated as a National Natural Landmark by the National Park Service.
Hell on Earth is the third studio album by the American hip hop duo Mobb Deep, released on November 19, 1996, through Loud and RCA Records. A sequel to Mobb Deep's previous album, the critically acclaimed The Infamous (1995), Hell on Earth is entirely produced by group member Havoc and features guest appearances from rappers Nas, Raekwon, Method Man, and frequent collaborator Big Noyd. The album includes the acclaimed singles "G.O.D. Pt. III" and "Hell on Earth ," as well as "Drop a Gem on 'Em," a response to 2Pac's diss track "Hit 'Em Up." A promotional single, "Still Shinin'", was released earlier that year and later added to the album.
Caenagnathidae is a family of bird-like maniraptoran theropod dinosaurs from the Cretaceous of North America and Asia. They are a member of the Oviraptorosauria, and close relatives of the Oviraptoridae. Like other oviraptorosaurs, caenagnathids had specialized beaks, long necks, and short tails, and would have been covered in feathers. The relationships of caenagnathids were long a puzzle. The family was originally named by Raymond Martin Sternberg in 1940 as a family of flightless birds. The discovery of skeletons of the related oviraptorids revealed that they were in fact non-avian theropods, and the discovery of more complete caenagnathid remains revealed that Chirostenotes pergracilis, originally named on the basis of a pair of hands, and Citipes elegans, originally thought to be an ornithomimid, named from a foot, were caenagnathids as well.
Hell on Earth may refer to:
The Hellboy Universe is the fictional universe of the Hellboy comic and its various spinoffs, created by Mike Mignola. Its first appearance was in a black-and-white, four-page promotional comic by Mike Mignola with a script by John Byrne published by Dark Horse Comics in San Diego Comic-Con Comics #2, distributed at the San Diego Comic-Con. The Hellboy Universe currently spans over eighty trade paperbacks. It is also sometimes informally called the "Mignolaverse".
B.P.R.D. Hell on Earth: New World is the first trade paperback collection in the Hell on Earth cycle of the B.P.R.D. series.
Acheroraptor is an extinct genus of dromaeosaurid theropod dinosaur known from the latest Maastrichtian Hell Creek Formation of Montana, United States. It contains a single species, Acheroraptor temertyorum. A. temertyorum is one of the two geologically youngest known species of dromaeosaurids, the other being Dakotaraptor, which is also known from Hell Creek. A basal cousin of Velociraptor, Acheroraptor is known from upper and lower jaw material.
The Cretaceous–Paleogene (K–Pg) extinction event, also known as the Cretaceous–Tertiary(K–T)extinction, was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the exception of some ectothermic species such as sea turtles and crocodilians, no tetrapods weighing more than 25 kilograms survived. It marked the end of the Cretaceous Period, and with it the Mesozoic era, while heralding the beginning of the Cenozoic era, which continues to this day.
A superhabitable planet is a hypothetical type of exoplanet or exomoon that may be better suited than Earth for the emergence and evolution of life. The concept was introduced in 2014 by René Heller and John Armstrong, who have criticized the language used in the search for habitable planets and proposed clarifications. According to Heller and Armstrong, knowing whether or not a planet is in its host star's habitable zone (HZ) is insufficient to determine its habitability: It is not clear why Earth should offer the most suitable physicochemical parameters to living organisms, as "planets could be non-Earth-like, yet offer more suitable conditions for the emergence and evolution of life than Earth did or does." While still assuming that life requires water, they hypothesize that Earth may not represent the optimal planetary habitability conditions for maximum biodiversity; in other words, they define a superhabitable world as a terrestrial planet or moon that could support more diverse flora and fauna than there are on Earth, as it would empirically show that its environment is more hospitable to life.
Proxima Centauri b, sometimes referred to as Alpha Centauri Cb, is an exoplanet orbiting within the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of the triple star system Alpha Centauri. It is about 4.2 ly (1.3 pc) from Earth in the constellation Centaurus, making it, along with the currently-disputed Proxima c, and Proxima d the closest known exoplanets to the Solar System.
Tyler Crook is an American comics artist. He broke into comics in 2011 with Petrograd, written by Philip Gelatt and published by Oni Press, and in 2012 he won the Russ Manning Most Promising Newcomer Award. He is best known for his work on Mike Mignola and John Arcudi's B.P.R.D.: Hell on Earth, Harrow County, which he co-created with Cullen Bunn, and his solo comic book series The Lonesome Hunters.
