Category: Solar System

This Day in Science, Technology, Astronomy, and Space Exploration History Astronomy Solar System

Halley’s Comet Made the Closest Approach to Earth on April 11, 1986

Post author By M. Özgür Nevres
Post date April 11, 2022
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On April 11, 1986, with about 63 million kilometers (39 million miles), Halley’s Comet made its closest approach to Earth on its outbound journey (while moving away from the Sun).

This Day in Science, Technology, Astronomy, and Space Exploration History Solar System Space Exploration

The first moon in orbit around an asteroid [243 Ida] was discovered on March 23, 1994

Post author By M. Özgür Nevres
Post date March 26, 2022
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Asteroid 243 Ida and its moon Dactyl — Asteroid Ida and its moon Dactyl, which is the first natural satellite discovered orbiting an asteroid. This image was obtained when the Galileo spacecraft flew past 243 Ida on August 28, 1993 and was released on March 23, 1994. Credit: NASA/JPL

On March 23, 1994, a photo was released showing the first moon discovered be in orbit around an asteroid, 243 Ida.

Today’s (March 23) story of what happened this day in Science, Technology, Astronomy, and Space Exploration history.

This Day in Science, Technology, Astronomy, and Space Exploration History Astronomy Solar System Space Exploration

Christiaan Huygens discovered Titan on March 25, 1655

Post author By M. Özgür Nevres
Post date March 25, 2022
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Titan orbiting Saturn — Larger than the planet Mercury, huge moon Titan is seen here as it orbits Saturn. Below Titan are the shadows cast by Saturn's rings. This natural color view was created by combining six images captured by NASA's Cassini spacecraft on May 6, 2012. Credits: NASA/JPL-Caltech/Space Science Institute

On March 25, 1655, the Dutch mathematician, physicist, astronomer, and inventor Christiaan Huygens discovered Titan, Saturn’s largest moon and the second-largest natural satellite in the Solar System (after Jupiter’s Ganymede).

Today’s (March 25) story of what happened this day in Science, Technology, Astronomy, and Space Exploration history.

This Day in Science, Technology, Astronomy, and Space Exploration History Astronomy Solar System

Cassini discovered Saturn’s moons Tethys and Dione on March 21, 1864

Post author By M. Özgür Nevres
Post date March 21, 2022
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On March 21, 1864, the Italian mathematician, astronomer, and engineer Giovanni Domenico Cassini (8 June 1625 – 14 September 1712) discovered Saturn’s moons Tethys and Dione. Cassini used a refractor telescope with an aperture of 108 mm to make this observation.

Today’s (March 21) story of what happened this day in Science, Technology, Astronomy, and Space Exploration history.

This Day in Science, Technology, Astronomy, and Space Exploration History Solar System Space Exploration

Giotto spacecraft made the closest approach to Halley’s Comet on March 13, 1986

Post author By M. Özgür Nevres
Post date March 13, 2022
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Artist rendering of Giotto spacecraft approaching Halley comet — Artist's rendering of European Space Agency's Giotto spacecraft approaching Halley's comet. By Andrzej Mirecki - Own work, CC BY-SA 3.0, Link

On March 13, 1986, European Space Agency‘s (ESA) Giotto spacecraft made the closest approach to Halley’s Comet at a distance of 596 kilometers (370 miles).

Today’s (March 13) story of what happened this day in Science, Technology, Astronomy, and Space Exploration history.

Solar System Moon Landing

Earth Phases as seen from the Moon

Post author By M. Özgür Nevres
Post date February 11, 2022
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A crescent Earth rising over the Moon, seen from Apollo 14 on February 6, 1971. This is a cropped and resized image. You can see the original image on NASA website.

Earth’s phases in the Moon’s sky are exactly the opposite of the Moon’s phases in the Earth’s sky. Is there a full moon? The Earth is dark in the Moon’s sky. It’s half-moon? The Earth is also half. Moon is a slim crescent? Earth is almost full.

Moon Landing Solar System Space Exploration

Can you see an astronaut on the Moon via a strong telescope? No, here’s why

Post author By M. Özgür Nevres
Post date January 25, 2022
No Comments on Can you see an astronaut on the Moon via a strong telescope? No, here’s why

Apollo 14 Commander Alan B. Shepard on the Moon — Astronaut Alan B. Shepard Jr., Apollo 14 commander, assembles a double core tube as he stands beside the rickshaw-type portable workbench or modularized equipment transporter (MET) unique to this mission. The photograph was taken by astronaut Edgar D. Mitchell, lunar module pilot, standing some 170 meters (560 feet) northeast of the Lunar Module (LM), during the mission's second extravehicular activity (EVA) on Feb. 6, 1971. While astronauts Shepard and Mitchell descended in the LM "Antares" to explore the Fra Mauro region of the moon, astronaut Stuart A. Roosa, command module pilot, remained with the Command and Service Modules (CSM) "Kitty Hawk" in lunar orbit. Apollo 14 was the eighth crewed mission in the United States Apollo program, and the third to land on the Moon. This photo was taken on February 6, 1971. This is a cropped and resized image. You can see the original photo on the NASA Spaceflight website.

As NASA plans to return to the moon, will we be able to see the astronauts on the Moon via a really strong telescope, when they were landed?

Solar System

ISS Transiting Moon over the Apollo 11 landing site! [Amazing video]

Post author By M. Özgür Nevres
Post date January 20, 2022
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International Space Station (ISS) transiting moon over the Apollo 11 landing site (featured) — International Space Station (ISS) transiting moon over the Apollo 11 landing site. This composite image is created by astrophotographer Andrew McCarthy. His website: Cosmic Background

Astrophotographer Andrew McCarthy published on his Twitter account an amazing video of the International Space Station (ISS) transiting the Moon, over the landing site of Apollo 11, the first moon landing mission. Such an incredible amount of human achievement is represented in just one short video!

Solar System Astronomy

Solar Eclipse Calculator: a nice tool by NASA

Post author By M. Özgür Nevres
Post date December 24, 2021
No Comments on Solar Eclipse Calculator: a nice tool by NASA

Sun's corona during 2017 Total Solar Eclipse. Photo Credit: NASA/Carla Thomas The Sun's corona, which is only visible during the total eclipse, is shown as a crown of white flares from the surface in the photo below. It was captured from onboard a NASA Gulfstream III aircraft flying 25,000 feet above the Oregon coast. The red spots called Bailey's beads⁽²⁾ occurs where the moon grazes by the Sun and the rugged lunar limb topography allows beads of sunlight to shine through in some areas.

Today I learned that there’s a solar eclipse calculator on the NASA website. Its official name is JavaScript Solar Eclipse Explorer (JSEX). Using this solar eclipse calculator, you can compute the local circumstances for every solar eclipse visible from a city for any century from -1499 to 3000 (1500 BCE to 3000 CE).

Space Exploration Solar System

Triumph at Saturn: Cassini’s Grand Voyage [Documentary]

Post author By M. Özgür Nevres
Post date December 5, 2021
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Cassini, artist conception — This is an artist's concept of Cassini during the Saturn Orbit Insertion (SOI) maneuver, just after the main engine has begun firing. The spacecraft is moving out of the plane of the page and to the right (firing to reduce its spacecraft velocity with respect to Saturn) and has just crossed the ring plane. The SOI maneuver, approximately 90 minutes long, allowed Cassini to be captured by Saturn's gravity into a five-month orbit. Image: NASA

NASA Jet Propulsion Laboratory (NASA JPL) has published a great documentary about Casini Spacecraft’s grand voyage (and its finale) around Saturn. Titled “Triumph at Saturn”, the two-part documentary chronicles the story of NASA’s Cassini mission.