Skytalk

Kepler scientists this week announced the 219 newest additions to the exoplanet count – 10 of which are identified as “terrestrial” – a far better word to use than “earthlike.” Terrestrial meaning rocky, comparable to earth in size, and in their star’s habitable zone. The total number of planet candidates now? 4,034. Confirmed? 2335 verified as planets. Kepler first looked in the Cygnus constellation region for these discoveries and this latest addition represents the end of its work in Cygnus. One conclusion – Half the planets in our galaxy are either rocky and larger than Earth or are like Neptune, smaller giant gas planets.

Next Monday is Aphelion: the follow-up to the summer solstice. Even now, we’re sitting right at 15 hours of sunlight per day, with long evenings.

The August 21st Solar Eclipse is less than 2 months away. Locally, it’ll be just partial. For totality, your closest vantage point is South Carolina, just a 12-hour drive from here. More information at fi.edu/eclipse.

Sun’s Original Twin: What happened to it? UC Berkeley astronomer Steven Stahler and Sarah Sadevoy of Smithsonian Astrophysical Observatory, have been studying how single stars form. Data collected in different surveys of the Perseus stellar nursery supports a model in which single stars seem to form first as binaries, then, depending on the distance between the stellar nuclei, they either stick together as binaries or break apart becoming single stars. The new study suggests this is how all single, low mass stars – sunlike stars – originally develop. So what happened to our star’s sibling? Because of the extreme distance between the two – 17x the distance between our star and the planet Neptune- the two nascent stars separated. One became our star while the other moved off to become one of the many other stars in this region of the Milky Way.

If you’re sweating from our current heat wave, be glad you don’t live on planet KELT-9, orbiting a blue A-type star 620 light years from Earth.

Saturn’s got the swing shift! Jupiter, then Saturn by 10p, by 4:30 a, Saturn in the west and Venus in the east – Saturn’s the planetary pivot of the sky! Anybody notice last week’s mini-moon? Didn’t think so… the difference in size was too small to notice!

Wiltshire, England doesn’t have the monopoly on solar events with summer solstice at Stonehenge. Philadelphia is a suitable site to take in an Equinox spectacle.

A cosmic debris ring has been observed around a star where a planet has already been directly observed.

Sunset now comes at 8:15pm, giving us 14 hours and 36 minutes of daylight here at Philadelphia’s latitude.

On Wednesday morning Venus, Uranus, Mercury and the Moon can be seen low in the east at 4:45 AM, along with a very bright ISS from Northwest to Southeast!

Astronomical Anniversaries of note;

How can we get into outer space faster? Nanocraft! The $100 million Breakthrough Starshot initiative intends to develop, within a generation, the capability to launch tiny laser-propelled space probes to the nearest star. The 1 gram, postage stamp-sized chips would have all the electronics necessary to collect data and transmit information back to us from the nearest star system. Driven by 100-gigawatt laser, the chips would accelerate up to 20% of the speed of light in two minutes and get them to the star in 20 years. Fronted by billionaire Yuri Milner and supported by Stephen Hawking and Mark Zuckerberg, the proposed project could cut 29,980 years off a conventionally propelled probe out to Alpha Centauri.

Gemini stands on the western horizon at 9:30 now, the last of the winter constellations. Mars is gone for this season of planet viewing, replaced by Jupiter immediately visible after sunset. By 12:45a Jupiter is well up in the south, with Saturn above the SE horizon stuck in the Milky Way portion of the sky between Sagittarius and the stars of Scorpius. Leo is in the NW, with UMaj – The Big Dipper, higher up in the north.

With the return of the summer constellations rising around midnight, the Milky Way rises up from ringing the horizon and will arc slowly across the night sky. We look to the west in one direction away from our galactic arms and in the opposite direction to the east as if we’re the hub of the wheel and the tire rolls around us but we’re way out near the far edge of the Milky Way with center being towards Sagittarius, found in our southern sky.

Now more commonly observed as a celebration of spring, in older times May 1st was considered the first day of summer in some European countries, with February 1 as the first of spring and June 21 marking midsummer.

The Blanco reflector telescope at Cerro Tololo in Chile has detected a ‘distant dwarf’ planet observers are calling “DeeDee.”