Skytalk

Weeks ago, an announcement about the discovery on an exoplanet where it appeared possible for an atmosphere with precipitation to exist led it to be described as an “earthlike planet,” and suggestions were made about its potential habitability.

Very little was said about its structure being far more like Jupiter mostly gas with a tiny rocky core very far below the cloud tops. That’s an important component of the composition in a description mentioning ‘habitability’ and ‘earthlike’.

This has implications for the composition of the planet and the dynamics of planetary formation in that star system. We are as yet unable to gather enough data to clearly identify something as TRULY earthlike. We can use only inference to determine mass, density, size and transmission spectroscopy to get any kind of handle on atmospheric composition.

Turning to night sky highlights this week:

The International Astronomical Union (IAU) is putting out the call on its 100th anniversary to name an exoplanet and its star.

The TV series ‘Star Trek’ premiered 53 years ago. The original series only lasted three seasons on prime time, but really hit its stride in syndication, where its popularity exploded. It also fueled fantasies for many other TV programs and films, and maybe even real life space exploration. The last day for filming was 1/8/69, six months before Apollo 11 left for the moon.

September means a shorter number of minutes of sunlight; Sunrise now at 6:34am and sunset at 7:23pm.

After a four-week journey from earth, the Indian Space Research Organization announced its Chandrayaan 2 spacecraft successfully entered lunar orbit. Next up in about a week is a landing attempt, then a rover deployment. The chosen landing location is the moon’s South Pole region. The orbiter is expected to operate for about a year and the lander and rover will perform surface studies. The rover is about 60 pounds and solar powered. The lander and rover are expected to last at least one lunar day (two weeks) but as lunar night comes flight controllers will try to awaken the rover and lander after the two-week sleep. India hopes to complete its first crewed mission by 2022.

The Big Dipper is visible in the northwest just after dark and the main summer constellations Cygnus, Lyra, and Altair are overhead by 9:00pm. Catch three seasons of constellations in one overnight: Summer Triangle overhead at 9:30pm, Pegasus and Andromeda (w/ M31) in the east at 10:30pm, and Orion in the east at 5:00am-5:30am. The moon is next to Jupiter on the evening of the 5th and slides towards Saturn the next night.

Nuclear Physicist Gunther Korschinek and his team of researchers from Technical University of Munich sifted through half-a-ton of snow from Antarctica to find 10 atoms(!) of Iron-60 an isotope (radioactive 60 protons, 60 neutrons in the nucleus) only produced in supernova explosions.

A diminishing amount of sunlight by mid-August triggers trees to start closing down – triggering a hormone that releases a chemical message to each leaf that it is time to prepare for winter. Over the next few weeks, abscission cells form a bumpy line at the place where the leaf stem meets the branch. And slowly, but surely, the leaf is “pushed” from the tree branch. This winterization process ensures trees’ survival. In spring and summer, leaves convert sunlight into energy through photosynthesis.

Tardigrades, also called water bears because of their microscopic teddy or panda bear-like appearance have been known to exist in a dormant state for a decade or more. Some have even survived hitchhiked rides on rockets to orbit and survived the deadly environment of space. The Israeli lunar mission was carrying several thousand of the microscopic critters when in crash-landed on the moon in April. They have the enviable ability to put themselves into a sort of state of suspended animation called cryptobiosis. In other words, when living conditions become less than ideal, they can curl themselves up, dry themselves out and become relatively impervious to the outside world until conditions improve. Given their ability to hibernate for decades, it’s remotely possible that some of them could be collected and re-animated (rehydrated) by future lunar explorers!

Although the Perseid Meteor Shower is the year’s best shower, it will be compromised this year due to an almost full moon that will make viewing a challenge.

Muddy Run Observatory Sky and Star Festival takes place today- A great family event, from noon to 11 p.m. at Muddy Run Park in Holtwood, PA. I’ll be presenting tonight in between telescopic observing at the region’s newest observatory under very dark skies.

Viewing highlights at the Franklin Institute Night Skies at the Observatory on Tuesday include the moon, Jupiter and Saturn.

GJ 357d is one of three planets found orbiting a tiny (300,000 miles diameter) M-type star 31 light years away.

The universe is primarily comprised of so-called “dark matter.” We can’t see it, but we know it exists because we can see its gravitational effect. Some physicists think dark matter is made up of weakly interacting massive particles (WIMPs), but they have yet to be detected.

Sunrise now at 6:01am and sunset at 8:12pm, we’ve already lost 49 minutes of daylight.

Upcoming cross-quarter day on August 1 is known as LoafMass: A celebration of the first loaves of bread from the first harvests of wheat in Northern Europe. The Celts called the day Lughnasadh, recognizing the fruits of the marriage of the Sun god Lugh and the Earth goddess. Other, better-known cross-quarter days are Beltane/May Day on May 1, Samhain/Halloween on October 31, and Candlemas/Groundhog Day on February 2.

We’re gathering new evidence about galactic sized mergers, including one in our Milky Way. Stars in our galaxy have been calculated to be 10 to 13 billion years old – as old as the oldest stars in the universe! They also indicate that the infant Milky Way was once impacted by a smaller galaxy that today is revealed by a distinct population of blue star scattered throughout the Milky Way.

Jupiter and Saturn dominate the cross-quarter evening sky now, straddling the Milky Way.

Today, July 20th, marks the 50th anniversary of mankind’s giant leap.

New moons have been spotted forming for the first time! PDS 70b and PDS 70c have been spotted in the disc of dust surrounding their giant planet around the star PDS 70. Combined optical, infrared, and radio data results show not only a protoplanetary disc around the star but also circumplanetary disc around its two largest planet – indicating the formation of moons around those Jupiter-like sized planets.

A new study suggests that moons of some exoplanets might be pulled away from their planet parents to become independent star orbiters – not planets . . . but ploonets.

50 years ago Tuesday, Apollo 11 astronauts left earth bound to become the first humans to step onto another celestial body. Neil Armstrong writes a check to pay personal debts before he leaves for the moon!

The Franklin Institute’s “Summer of the Moon” program cranks up next week with Night Sky Observatory programs on Tuesday and Thursday, with a full day of programming next Saturday, July 20.

Turning to the night sky – The moon slides past Jupiter tonight, then Saturn on Sunday evening. Full moon is Tuesday night.