Monthly Archives: May 2020

Local Kids Feel Connection to New Spacecraft Set to Explore Mars

NASA Mars 2020 Rover

Graphic courtesy of NASA.

Local students will be taking special interest in a Mars mission this summer. A student from Lake Braddock Secondary School named the U.S. rover 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 children develop a plan for exploring a crater on Mars by using small rover models that the students made themselves. It gave the kids a feel for creating a mission plan and was a great warm-up for the real mission NASA launches in July.


Bill Burton works with students at The Turner Farm on mock-ups of a Mars mission.

Timing is everything with these Mars missions. The Analemma Society’s Shawn Dilles 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 farther from the sun, and a bit slower, and 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.

Mars was last in conjunction on September 2, 2019, when it was 248,192.005 miles from Earth. On October 13, 2020, Mars will be in opposition at 38.6 million miles from Earth, about one-sixth the distance at the farthest point.

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. 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 where Mars is in its orbit, so that by the time they arrive, Mars will have “caught up” to this position.

The U.S., 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 will 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 by Alexander Mather, a 7th 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 data on the best routes to take. The goal is 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.

Author Shawn Dilles is a volunteer with the Analemma Society who teaches classes at the Park Authority’s Observatory Park at The Turner Farm.


A Weedy Knoll is Transformed into a Native Garden at South Run


An unsightly, weedy knoll that was once filled with dead trees and poison ivy has been undergoing a transformation at South Run District Park. Though park visits have recently been restricted due to COVID-19, volunteers have been keeping their social distance from each other and continuing this environmentally-friendly beautification project.

The work near the entrance to South Run RECenter began in 2014. At that time, the area was covered with dead pine trees, poison ivy and a tangle of non-native invasive plants. The Fairfax County Park Authority and a volunteer team led by Sally Berman launched an effort to clear the knoll and introduce a combination of perennials that folks donated from their own yards. Kurt Lauer, the Volunteer Coordinator for South Run RECenter, supervised the effort for the Park Authority.

This year, a second transformation of the knoll has been taking place under the leadership of Sherry McDonald, a Fairfax Master Naturalist who has joined the volunteer landscaping team at South Run. Under McDonald’s lead, a plan was developed to add


Sherry McDonald planting native plants at South Run.

dozens of native plants to the knoll. “Even with the uncertainty of everything due to COVID-19, volunteers have been working to create the ‘Natives Knoll,’ the whole time following physical guidelines,” said McDonald.  “We developed a plan with the guidance of Matt Bright, who runs a non-profit organization called Earth Sangha which grows native plants for our area.”

South Run RECenter purchased more than 90 native plants for the landscaping effort. The plants from Earth Sangha include Golden Alexanders, wild bergamot, spotted beebalm and black-eyed Susans. McDonald contributed some golden ragwort. Berman added kalameris, ironweed and coneflowers. The garden will eventually include Maryland gold aster, thoroughwort, purple lovegrass, butterfly weed, hairy beard tongue, golden rod and wild geranium, too.


Sally Berman burying cardboard with mulch. The cardboard makes a good weed barrier and will decompose and enrich the soil.

Because the plants needed to get into the ground, the South Run volunteers were granted special permission to work because of the time sensitivity of their project. The volunteers have been diligent in their social distancing and adopted new safety procedures for their work. Sections of garden have been assigned to specific volunteers so that they aren’t working in the same areas. The volunteers are using their own tools and not sharing anything. All planning is being coordinated via phone, text and email.

McDonald, Berman and other members of the landscaping team view gardening as both physical and mental therapy during these uncertain times.  They hope that when the park reopens, people will stop to view their handiwork on this up-and-coming Natives Knoll, but they caution it will take some time for all the plants to fill in. The volunteers estimate it will be a couple years before the plants reach their peak beauty.

April 2020

The transformed knoll in April 2020.

“In the future, this garden will include plant signage, and we hope it will be certified as an Audubon at Home wildlife sanctuary,” said McDonald.  “We hope the garden will attract birds, pollinators and human visitors.  Maybe some people will even be inspired to join our landscaping team!”

Author Carol Ochs works in the Park Authority’s Public Information Office.

Murder Most Fowl

crowsHumans may travel in teams, cozy up into cliques, form a sorority or be members of an old boys’ club, but what do we call gatherings of other living things? You probably know that a group of cattle or deer form a herd, but did you know that a group of cockroaches is called an intrusion? Not too surprising.

Fox at Feeder-InstaYou don’t have to think very hard to figure out why some groups of animals got their names. Have you ever seen a pounce of cats or heard a cackle of hyenas? Maybe you’ve have the misfortune to cross through a cloud of grasshoppers or gnats. Hopefully you’ve never been surrounded by a leap of leopards or a skulk of fox.

Did you know that a group of chubby-looking hippos is actually called a bloat? You also can call them hippopotamuses or hippopotami. Either is correct. It’s not surprising that several giraffes gathered in one spot might be called a tower, and it seems fitting that a group of flamingoes is known as a flamboyance.

Some group names seem to reflect the personality of the animals. Lions travel in a pride.  Apes, just a step down the evolutionary ladder from us, are called a shrewdness when gathered together. Crows and ravens, which have picked up a bad reputation from movies and literature, don’t have very good group names either. A gathering of crows is called a murder. A bunch of ravens is known as an unkindness.

DSC_0082A group of birds in the air is called a flight while a group on the ground is generically called a flock. Various species have received their own group names over the years. You might see a sedge of bitterns, a chain of bobolinks, a brood of chicks or a gulp of cormorants. Doves gather in a dule and ducks form a brace. Majestic eagles form a convocation while geese gather on the ground in a gaggle. Look for a colony of gulls at the seashore or a cast of hawks in the mountains. You might be tempted to scold a scold of jays when they get together in a party. Rooks form a building, turkeys group together in a rafter and woodpeckers form a descent.

You may have nothing to fear from the congregation at church on Sunday, but if you see a congregation of alligators, you might want to say a prayer. If one shark makes you shake, what would you do around a shiver of sharks? Don’t be tempted to reach out and touch any porcupines. They gather in a prickle.


Frogs, herring and caterpillars travel in an army. Groups of kangaroos are called a troop. Monkeys can gather in a troop, too, but they’re better known by another name. After all, what could be more fun than a barrel of monkeys?

Author Carol Ochs works in the Park Authority Public Information Office. This article first appeared in the ResOURces newsletter.