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Category: Activities

Published: 27 May 2020

One hundred twenty years ago a Greek sponge diver off the coast of a small island named Antikythera in the Aegean Sea discovered a Roman shipwreck. The ship was filled with looted Greek treasures traveling from Rhodes to Rome to deliver its precious cargo.  But misfortune caused the ship to sink.

Among the artifacts the divers found a calcified bronze lump, aggregated into a solid mass by 20 centuries of time.  Originally thought to be an astrolabe, investigations by Derek de Solla Price in 1959 changed all of that.  In an article for Scientific American titled "An Ancient Greek Computer".  Further analysis by Price published in the Philadelphia American Philosophical Society's journal documented "Gears From the Greeks" using X-rays taken by Kr. Karakalos to show that this calculator was an astronomical calculator and predictor.  The clockwork complexity was 1500 years ahead of its time, allowing accurate predictions of solar eclipses and the phase of the moon.

Since then more than a dozen working models of the Antikythera device have been made (with some speculation as to gearing).  In 2015 Kyle MacInnis in an article "An Examination of the Antikythera Mechanism" describes the main features: "the presence of two spiral dials on one side representing the Saros (Eclipse Periodicity) and Metonic (Solar and Lunar Periodicity) cycles; on the opposing side, a third dial showing position of the Sun and the Moon as well as the Moon's phase, and calendrical information pertaining to the date such as month, zodiac, and day.

Join the adventure, download the article by Kyle MacInnis and watch the video:

You can see this video and all 10 episodes on YouTube starting at:

https://www.youtube.com/watch?v=ML4tw_UzqZE

Attachments:

An_Examination_of_the_Antikythera_Mechanism.pdf

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1378 kB

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Category: Activities

Published: 21 May 2020

Bill Burton with students at Turner Farm earlier the year. As safety guidelines permit, Observatory Park at The Turner Farm will again be offering astronomy-themed classes on Mars, stars and constellations, and other celestial events. Check Parktakes online and the Analemma Society website for updates on programming.

Local students will be taking special interest in a NASA Mars mission this summer. A student from Lake Braddock Secondary School named the U.S. rover called Perseverance that will land on the planet’s surface, and students in a Park Authority science program worked on a mock-up of a Mars mission of their own.

Before astronomy programs at The Turner Farm observatory were canceled because of the COVID-19 pandemic, a group of students spent time studying Mars with an instructor from the Analemma Society. Bill Burton helped the students develop a plan for exploring a crater on Mars by using small rover models that the students made themselves. It gave the students a feel for creating a mission plan and was a great warm-up for the real NASA mission that launches in July 2020. Timing is everything with these Mars missions. The Analemma Society’s Shawn Dilles (who volunteers and teaches classes at Turner Farm provides the details:

"Every two years, NASA and a few other national space agencies launch new probes toward the planet Mars to join the other spacecraft already in operation there to explore the red planet. The timing of the launches is not a coincidence. Earth and Mars both orbit the sun in the same direction, but Earth completes an orbit in just over 365 days (one Earth Year). Mars is further from the sun, and traveling slower completes one orbit every 687 days (one Mars Year)."

"Because they are travelling at different speeds through their orbits, the distance between Earth and Mars varies throughout the Martian Year. At the closest point, Earth is positioned between Mars and the Sun – a time called opposition since Mars is opposite the Sun from Earth. Opposition between Earth and Mars occurs every two years and 50 days. Earth and Mars are farthest apart when on opposite sides of the sun from each other, and this is known as a conjunction."

"Observers on Earth are able to track the time when Earth “laps”’ Mars when travelling around the sun. Planets generally move from east to west relative to the background constellations. For a brief time before, during and after opposition, Mars will appear to slow, stop and move backwards toward the west. This apparent retrograde motion of Mars is because Earth appears to catch up to and then pass Mars. In 2020, Mars will be in the constellation Pisces, and the retrograde motion will occur from September 9 to November 14."

"Rocket scientists use the difference in orbital positions and speeds to advantage. The goal is to minimize the amount of fuel and time needed to get to Mars, in order to allow the most payload possible to be flown. The spacecraft are aimed at a point ahead of the where Mars is in its orbit, so that by the time they arrive, Mars will have “caught up” to this position."

 

"The United States, China, and the United Arab Emirates have each scheduled launches to Mars in July 2020. If successful, these spacecraft will join the Curiosity Rover and six orbiting spacecraft (Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, Mars Orbiter Mission, MAVEN and the Trace Gas Orbiter) at the planet."

 

"NASA’s Mars 2020 mission be launched around July 17, and it is based on the Mars Science Laboratory design. It will include an improved rover called “Perseverance” that was named Alexander Mather, a 7^th grader at Lake Braddock Secondary School in Burke, as part of a NASA naming contest. The mission will also carry a small helicopter named “Ingenuity”  -- the first aircraft sent by Earth to another world. Vaneeza Rupani, an 11th grade student from Alabama, suggested the name Ingenuity. The helicopter will fly ahead of the rover to provide mission planners with the data on the best routes to take. The exploration goals are to explore the area around Jezero Crater, believed to have once been an ancient lakebed."

 

"China’s Tianwen-1 lander and a rover are scheduled to land in Utopia Planitia to seek evidence of past life on Mars and study the planet’s surface and environment. A Chinese orbiter will study the Martian atmosphere, ionosphere, ice and surface topography. The United Arab Emirates orbiter will study the Martian atmosphere and weather, including dust storms on the planet."

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Category: Activities

Published: 09 May 2020

While Comet Atlas breaks up as it journeys toward the sun Sky and Telescope reports a new and spectacular comet now graces our evening sky.  As Sky & Tel notes, Comet SWAN was observed on March 25th by Australian amateur Michael Mattiazzo as the comet "brightened by leaps and bounds....As of May 5th, the newcomer had climbed to magnitude 5.2 with a 1° visual tail that lengthens to a luxurious 6–8° in photographs."

With binoculars scan the eastern skies just before dawn and close to the horizon.  You may be able to see Comet SWAN for yourself.  Astronomer Con Stoitsis says "It should be an 'obvious' naked eye target in mid-May."  But the comet is fast moving. It makes its closest approach to the earth on May 13 and reaches perihelion (closest approach to the sun) on May 27.  You can check the current coordinates and status of Comet SWAN (C/2020 F8) at https://theskylive.com/

The photo is a planetarium representation of the morning sky just before dawn on May 10th from Washington D.C. at latitude 39 N.

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Category: Activities

Published: 12 April 2020

On April 8th the Mark Slade Remote Observatory (MSRO) streamed a live viewing session of Comet Altas (C 2019 Y4) using a 102mm F/7 APO refractor and monochrome QHY 174 M camera. They are now sharing this event on video through You Tube.  MSRO's mission is to "Use state-of-the-art small-telescope systems to preserve and maintain public involvement in the astronomical sciences, offer observing and research opportunities for amateur and professional astronomers, and provide astronomical education to the general public." So, want to see a comet?