Planet that is composed primarily of silicate rocks or metals.
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Astronomy Daily — S05E147: "Space Mechanic" Wednesday 22 July 2026 A spacecraft with robotic arms is on its way to geostationary orbit to keep other satellites alive. A discarded rocket stage is two weeks out from hitting the Moon, and twenty-three astronomers have just asked the world to watch. Plus the first binary star system where both stars exploded, the first complete magnetic map of a galaxy cluster, and the asteroid breakup that may have bombarded three worlds while Earth froze. In This Episode ● The Space Mechanic Launches — Northrop Grumman's Mission Robotic Vehicle lifted off from Cape Canaveral on 21 July carrying three Mission Extension Pods. With two 3-metre robotic arms built by the US Naval Research Laboratory, it is designed to inspect, relocate, repair and refuel satellites in geostationary orbit. Each pod can give a 2,000 kg satellite up to eight more years of life. ● UPDATE — The Rocket Aimed at the Moon — A new arXiv preprint signed by 23 astronomers calls for a coordinated observing campaign when Falcon 9 upper stage 2025-010D strikes the Moon near Einstein crater on 5 August. North America has the best seat: 2:34am EDT, with the paper naming observers in the Americas as the ideal group. Refined impact time, predicted crater size, and why the ejecta plume may be visible even if the flash is not. ● Sibling Supernovae — Sixteen years of Fermi data reveal a faint supernova remnant hiding in the glare of the Jellyfish Nebula. The two may be the first known pair of remnants traced back to a single binary star system. ● Mapping a Cluster's Magnetic Field — Using the deepest radio observations ever made with LOFAR, astronomers have reconstructed the magnetic field of galaxy cluster Abell 2255 from nucleus to outer edge for the first time. ● The Eulalia Bombardment — A new Planetary Science Journal paper links the breakup of a main-belt asteroid to an impact shower that battered the Moon, Earth and Mars 800 million years ago — and may connect to a global freeze. ● Skywatch, Both Hemispheres — Why this week beats peak night for the Delta Aquariids wherever you are, how to catch them from the southern US and Mediterranean, and what's coming on 12 August: a total solar eclipse across Iceland and Spain, a North American partial, and the best Perseid peak in years on a new Moon.Sources & Further Reading ● Space.com — SpaceX launches satellite repair drone with 10-foot robotic arms to Earth orbit ● NASASpaceflight.com — Falcon 9 to launch MRV-1 robotic servicing spacecraft for Northrop Grumman ● Northrop Grumman SpaceLogistics — Mission Robotic Vehicle and Mission Extension Pod fact sheets ● Scientific American — A SpaceX rocket is about to crash into the moon; scientists will be watching ● Phys.org — When a SpaceX rocket crashes into the moon, scientists will be watching (arXiv preprint) ● Project Pluto (Bill Gray) — Upper stage impacting the moon on 2026 August 5 ● Stanford University — Researchers uncover evidence for sibling supernovas (Michailidis et al., Nature Communications) ● Reuters — Scientists spot evidence of two huge companion stars that blew up ● Space.com — Galaxy cluster's magnetic field reconstructed for 1st time with record-breaking astronomy map (Botteon et al., INAF, A&A) ● Southwest Research Institute — SwRI-led research connects asteroid collision to impact showers 800 million years ago ● The Planetary Science Journal — Bottke, Vokrouhlický, Dykhuis & Zellner, "An 800 Myr-old Impact Shower on the Terrestrial Planets from the Breakup of the Eulalia Parent Body" ● EarthSky — Delta Aquariid meteor shower: all you need to know in 2026 ● NASA Science — Total Solar Eclipse on August 12, 2026 (path, partial visibility and safety guidance) ● BBC Sky at Night Magazine — August 12, 2026 solar eclipse: USA and Canada guide Connect ● Website: astronomydaily.io ● Socials: @AstroDailyPod ● Part of the Bitesz.com Podcast NetworkBecome a supporter of this podcast: https://www.spreaker.com/podcast/astronomy-daily-latest-space-news--5648921/support.Sponsor Details:Ensure your online privacy by using NordVPN. To get our special listener deal and save a lot of money, visit www.astronomydaily.io/nordvpn. You'll be glad you did!Get the best secure and private email on the planet. Stop your Government, google and who knows who else spying on every email you write. Do what we did and use ProtonMail. They beleive in privacy and there are no ads in their business model...yet they still provide a free forever service. Check them out and get out special deal at www.astronomydaily.io/protonmailBecome a supporter of Astronomy Daily by joining our Supporters Club. Commercial free episodes daily are only a click way... Click HereThis episode includes AI-generated content.
Édouard BardCollège de FranceÉvolution du climat et de l'océanAnnée 2025-2026Session 1: The Planets of Our Solar System and How They WorkColloque - La Terre, une planète dynamique : un hommage à Xavier Le PichonIntervenant(s)Alessandro MorbidelliProfesseur du Collège de France
When did the first terrestrial planets form? How can galaxies collide when the Universe is expanding? Do black holes have Lagrange points? Answering all these questions and more.
When did the first terrestrial planets form? How can galaxies collide when the Universe is expanding? Do black holes have Lagrange points? Answering all these questions and more.
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This episode will be a comparison between our inner rocky planets and our mighty gas giants. --- Send in a voice message: https://anchor.fm/miguel-mena4/message
On today's ID the Future geologist Casey Luskin explains how Earth contains many intricate geological processes required for life. He argues that, taken together, this points to intelligent design rather than dumb luck. This episode is the first half of a talk Dr. Luskin presented at the 2022 Dallas Conference on Science and Faith. Stay tuned for Pt. 2 and a Q&A with his original audience. Source
A Note on the "Various Atmospheres over Water Oceans on Terrestrial Planets with a One-Dimensional Radiative-Convective Equilibrium Model by Tetsuya Hara et al. on Sunday 16 October It has been investigated the possibility of the various atmospheres over water oceans. We have considered the H$_2$ atmosphere and He atmosphere concerning to N$_2$ atmosphere over oceans. One of the main subjects in astrobiology is to estimate the habitable zone. If there is an ocean on the planet with an atmosphere, there is an upper limit to the outgoing infrared radiation called the Komabayashi-Ingersoll limit (KI-limit). This limit depends on the components of the atmospheres. We have investigated this dependence under the simple model, using the one-dimensional gray radiative-convective equilibrium model adopted by Nakajima et al. (1992). The outgoing infrared radiation ($F_{IRout}$) with the surface temperature ($T_s$) has shown some peculiar behavior. The examples for H$_2$, He, and N$_2$ background gas for H$_2$O vapour are investigated. There is another limit called the Simpson-Nakajima limit (SN-limit) mainly composed of vapour. This steam limit does not depend on the background atmosphere components. Under super-Earth case ($g=2times$9.8 m/s$^2$), several cases are also calculated. The KI-limit dependence on the initial pressure is presented. The various emission rates by Koll & Cronin (2019) are investigated. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05963v2
A Note on the "Various Atmospheres over Water Oceans on Terrestrial Planets with a One-Dimensional Radiative-Convective Equilibrium Model by Tetsuya Hara et al. on Sunday 16 October It has been investigated the possibility of the various atmospheres over water oceans. We have considered the H$_2$ atmosphere and He atmosphere concerning to N$_2$ atmosphere over oceans. One of the main subjects in astrobiology is to estimate the habitable zone. If there is an ocean on the planet with an atmosphere, there is an upper limit to the outgoing infrared radiation called the Komabayashi-Ingersoll limit (KI-limit). This limit depends on the components of the atmospheres. We have investigated this dependence under the simple model, using the one-dimensional gray radiative-convective equilibrium model adopted by Nakajima et al. (1992). The outgoing infrared radiation ($F_{IRout}$) with the surface temperature ($T_s$) has shown some peculiar behavior. The examples for H$_2$, He, and N$_2$ background gas for H$_2$O vapour are investigated. There is another limit called the Simpson-Nakajima limit (SN-limit) mainly composed of vapour. This steam limit does not depend on the background atmosphere components. Under super-Earth case ($g=2times$9.8 m/s$^2$), several cases are also calculated. The KI-limit dependence on the initial pressure is presented. The various emission rates by Koll & Cronin (2019) are investigated. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05963v2
A Note on the "Various Atmospheres over Water Oceans on Terrestrial Planets with a One-Dimensional Radiative-Convective Equilibrium Model by Tetsuya Hara et al. on Wednesday 12 October It has been investigated the possibility of the various atmospheres over water oceans. We have considered the H$_2$ atmosphere and He atmosphere concerning to N$_2$ atmosphere over oceans. One of the main subjects in astrobiology is to estimate the habitable zone. If there is an ocean on the planet with an atmosphere, there is an upper limit to the outgoing infrared radiation called the Komabayashi-Ingersoll limit (KI-limit). This limit depends on the components of the atmospheres. We have investigated this dependence under the simple model, using the one-dimensional gray radiative-convective equilibrium model adopted by Nakajima et al. (1992). The outgoing infrared radiation ($F_{IRout}$) with the surface temperature ($T_s$) has shown some peculiar behavior. The examples for H$_2$, He, and N$_2$ background gas for H$_2$O vapour are investigated. There is another limit called the Simpson-Nakajima limit (SN-limit) mainly composed of vapour. This steam limit does not depend on the background atmosphere components. Under super-Earth case ($g=2times$9.8 m/s$^2$), several cases are also calculated. The KI-limit dependence on the initial pressure is presented. The various emission rates by Koll & Cronin (2019) are investigated. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05963v1
A Note on the "Various Atmospheres over Water Oceans on Terrestrial Planets with a One-Dimensional Radiative-Convective Equilibrium Model by Tetsuya Hara et al. on Wednesday 12 October It has been investigated the possibility of the various atmospheres over water oceans. We have considered the H$_2$ atmosphere and He atmosphere concerning to N$_2$ atmosphere over oceans. One of the main subjects in astrobiology is to estimate the habitable zone. If there is an ocean on the planet with an atmosphere, there is an upper limit to the outgoing infrared radiation called the Komabayashi-Ingersoll limit (KI-limit). This limit depends on the components of the atmospheres. We have investigated this dependence under the simple model, using the one-dimensional gray radiative-convective equilibrium model adopted by Nakajima et al. (1992). The outgoing infrared radiation ($F_{IRout}$) with the surface temperature ($T_s$) has shown some peculiar behavior. The examples for H$_2$, He, and N$_2$ background gas for H$_2$O vapour are investigated. There is another limit called the Simpson-Nakajima limit (SN-limit) mainly composed of vapour. This steam limit does not depend on the background atmosphere components. Under super-Earth case ($g=2times$9.8 m/s$^2$), several cases are also calculated. The KI-limit dependence on the initial pressure is presented. The various emission rates by Koll & Cronin (2019) are investigated. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05963v1
Climate of high obliquity exo-terrestrial planets with a three-dimensional cloud system resolving climate model by Takanori Kodama et al. on Tuesday 11 October Planetary climates are strongly affected by planetary orbital parameters such as obliquity, eccentricity, and precession. In exoplanetary systems, exo-terrestrial planets should have various obliquities. High-obliquity planets would have extreme seasonal cycles due to the seasonal change of the distribution of the insolation. Here, we introduce the Non-hydrostatic ICosahedral Atmospheric Model(NICAM), a global cloud-resolving model, to investigate the climate of high-obliquity planets. This model can explicitly simulate a three-dimensional cloud distribution and vertical transports of water vapor. We simulated exo-terrestrial climates with high resolution using the supercomputer FUGAKU. We assumed aqua-planet configurations with 1 bar of air as a background atmosphere, with four different obliquities ($0^{circ}$, $23.5^{circ}$, $45^{circ}$, and $60^{circ}$). We ran two sets of simulations: 1) low-resolution (~ 220 km-mesh as the standard resolution of a general circulation model for exoplanetary science) with parametrization for cloud formation, and 2) high-resolution (~ 14 km-mesh) with an explicit cloud microphysics scheme. Results suggest that high-resolution simulations with an explicit treatment of cloud microphysics reveal warmer climates due to less low cloud fraction and a large amount of water vapor in the atmosphere. It implies that treatments of cloud-related processes lead to a difference between different resolutions in climatic regimes in cases with high obliquities. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05094v1
Climate of high obliquity exo-terrestrial planets with a three-dimensional cloud system resolving climate model by Takanori Kodama et al. on Tuesday 11 October Planetary climates are strongly affected by planetary orbital parameters such as obliquity, eccentricity, and precession. In exoplanetary systems, exo-terrestrial planets should have various obliquities. High-obliquity planets would have extreme seasonal cycles due to the seasonal change of the distribution of the insolation. Here, we introduce the Non-hydrostatic ICosahedral Atmospheric Model(NICAM), a global cloud-resolving model, to investigate the climate of high-obliquity planets. This model can explicitly simulate a three-dimensional cloud distribution and vertical transports of water vapor. We simulated exo-terrestrial climates with high resolution using the supercomputer FUGAKU. We assumed aqua-planet configurations with 1 bar of air as a background atmosphere, with four different obliquities ($0^{circ}$, $23.5^{circ}$, $45^{circ}$, and $60^{circ}$). We ran two sets of simulations: 1) low-resolution (~ 220 km-mesh as the standard resolution of a general circulation model for exoplanetary science) with parametrization for cloud formation, and 2) high-resolution (~ 14 km-mesh) with an explicit cloud microphysics scheme. Results suggest that high-resolution simulations with an explicit treatment of cloud microphysics reveal warmer climates due to less low cloud fraction and a large amount of water vapor in the atmosphere. It implies that treatments of cloud-related processes lead to a difference between different resolutions in climatic regimes in cases with high obliquities. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05094v1
The 365 Days of Astronomy, the daily podcast of the International Year of Astronomy 2009
https://youtu.be/ZZdbQXOwT40 We continue our refreshed tour of the solar system, checking in on the inner terrestrial planets, Mercury, Venus, Earth and Mars. What have we learned about the formation, evolution and what they might tell us about planets across the Universe. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too! Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
We continue our refreshed tour of the solar system, checking in on the inner terrestrial planets, Mercury, Venus, Earth and Mars. What have we learned about the formation, evolution and what they might tell us about planets across the Universe.
Astronomy Cast Ep. 626: Terrestrial Planets - Mercury, Venus, Earth & Mars by Fraser Cain & Dr. Pamela Gay We continue our refreshed tour of the solar system, checking in on the inner terrestrial planets, Mercury, Venus, Earth and Mars. What have we learned about the formation, evolution and what they might tell us about planets across the Universe.
In this month's bonus episode, Alice quickly covers NASA's origins and the first four planets in our solar system--often called the terrestrial (or rocky) planets.
Chris and Shane talk about some easy guide stars for the summer sky and an overview of the terrestrial planets.
Jupiter is the first of the gas giant planets. Let's take a look at what makes these planets different from the inner planets. It has a fascinating set of moons that help make up the Jovian system, and we find out how it subtle set of planetary rings were discovered.Follow Cosmic Coffee Time on Twitter for some special content twitter.com/CosmicCoffTimeYou can request a topic for the show! Or even just say hi!We'd love to hear from you.Email it to cosmiccoffeetime@gmail.com
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The episode focuses on the four planets that are closest to the Sun. Chris and Shane also talk about an interesting Mercury and Venus pairing to observe on May 23, 2020.
Prof Alessandro Morbidelli of the Observatoire de la Cote d'Azur in Nice gives the 2nd Lobanov-Rostovsky Lecture in Planetary Geology. He talks about the formation of planets in the universe. Morbidelli uses numerical modelling and geochemical and cosmochemical analyses to explain planetary formation within our solar system. He provides a growth history of the Earth, with reference to the specific elements found in the Earth mantle, as well as insight into the composition and timing of moon formation.
David Jewitt, professor of Earth & Space Sciences and Physics & Astronomy at UCLA, gives a modern broad view of our solar system and planetary systems of other stars. Series: "UCLA Science Faculty Research Colloquium" [Science] [Show ID: 21104]
David Jewitt, professor of Earth & Space Sciences and Physics & Astronomy at UCLA, gives a modern broad view of our solar system and planetary systems of other stars. Series: "UCLA Science Faculty Research Colloquium" [Science] [Show ID: 21104]
David Jewitt, professor of Earth & Space Sciences and Physics & Astronomy at UCLA, gives a modern broad view of our solar system and planetary systems of other stars. Series: "UCLA Science Faculty Research Colloquium" [Science] [Show ID: 21104]
David Jewitt, professor of Earth & Space Sciences and Physics & Astronomy at UCLA, gives a modern broad view of our solar system and planetary systems of other stars. Series: "UCLA Science Faculty Research Colloquium" [Science] [Show ID: 21104]
Transcript: We can use the idea of remote sensing of terrestrial planets in our own solar system to get an idea of what features we might look for in other planets around other stars. If we looked at the atmosphere of Venus with an infrared spectrum, we would see the strong absorption from carbon dioxide at fifteen microns and a more subtle absorption feature at eleven or twelve microns from sulfuric acid in the atmosphere. If we looked at Mars, we’d see the strong signature of its primary ingredient, carbon dioxide, in absorption at fifteen microns. If we looked at the Earth, we would see three interesting things. Carbon dioxide tracer would be there and also a strong edge due to water at about five or six microns. There would also be a deep absorption trough at about nine microns due to ozone. Ozone, a byproduct of oxygen, is a non-equilibrium gas and in the view of the Earth’s atmosphere from afar would be the strongest indication of life on this planet.
Transcript: Virtually every extrasolar planet found so far, and there are over a hundred, is an object like Jupiter or Saturn. These gas rich planets with giant atmospheres probably have conditions in their interiors that are utterly inhospitable for life. This fact is significant because the techniques used to find the extrasolar planets could have found objects ten times less massive than Jupiter and orbits considerably larger than the Jupiter orbit, and yet they have not found such systems. This raises the possibility that terrestrial planets or Earth-like planets might be unusual or rare. There is no way for us to know for sure, but it’s lead to a hypothesis called the Rare Earth Hypothesis. For example, in the known extrasolar planet systems, the presence of a giant planet so close to a star would act to eject smaller planets by the gravitational sling shot mechanism. So terrestrial planets or Earth-like planets could not exist in these systems except as moons. Until we find larger samples of extrasolar planets, we will not know how rare Earths might be.
Transcript: Each technique that is currently used to successfully detect extrasolar planets with a mass of Jupiter or larger could eventually and potentially be used to detect terrestrial planets or Earth-like objects. The direct detection technique is very difficult for Earths. The Sun outshines Jupiter by a factor of a billion, but the Earth by a factor of ten billion. The way to improve this experiment is to move into the infrared where the contrast improves by a factor of a thousand. A transit experiment can also be used. In an edge-on orbit, Jupiter would dim the Sun by one percent for one day every twelve years, and Earth, being ten times smaller, would dim the Sun by a hundred times less or only 0.01 percent, a tiny effect. The Doppler effect that has been used successfully to detect most extrasolar planets discovered so far requires extraordinary sensitivity if it’s used to detect Earths. The Sun pivots about its edge caused mostly by Jupiter, and so the detection of Jupiter requires a velocity precision of thirteen meters per second. Detecting an Earth with this technique requires a precision of 0.09 meters per second. Finally, the gravitational lensing technique, where brief magnification of a background star is caused by an intervening planet, can be used quite well to detect Earth-mass objects as well as Jupiter-mass objects. All of these techniques have an interesting prospect in the next ten or twenty years to succeed in detecting Earths. Probably they will have to be experiments done from space.
Transcript: The process of accretion swept up material to form Mercury to Earth-sized objects in the inner solar system, thus explaining the terrestrial planets. The content of these planets is material that can condense at the high temperatures at the inner solar nebula, thus it is mostly metallic and silicate material familiar to us in everyday rocks. These planets were relatively small. All leftover material was blown out of the inner solar system by the intense radiation field of the young Sun.
Astronomy 161 - Introduction to Solar System Astronomy - Autumn 2007
Astronomy 161 - Introduction to Solar System Astronomy - Autumn 2007