Skytalk

The successor to the highly successful Kepler planet-hunting satellite TESS (Transiting Exoplanet Survey Satellite) sent the first data down last week. TESS was launched April 18, and settled into orbit and sent its first data two weeks ago, a photo of near-Sun space containing 200,000 stars, many of which could be accompanied by at least one planet. Kepler looked at just one small region of sky; TESS will survey almost the entire sky, concentrating on about 20,000 stars where it’s expected to turn up as many as 10,000 new planets, many of which orbit stars we already know well.

TESS uses the newest, most accurate map of the Milky Way ever made, the Gaia Project map. The catalog that goes with the map contains the positions, distances, motions, brightness, and colors of more than 1.3 billion stars. Also provides the surface temps of about 100 million stars and the effect of interstellar dust on 87 million stars! TESS will use the map’s accuracy to pinpoint the stars it really wants to concentrate on. A project of the European Space Agency, Gaia was launched in 2013 on a five-year mission to map the Milky Way. It doesn’t orbit Earth but sits at a gravitational balance point of Earth moon and sun a million miles from earth.

The moon is near Saturn tonight and Mars Wednesday night. If you have a chance to see Mars through a telescope anywhere, do it since it looks quite large and good!

The current (approximately 11-year-long) Solar Cycle is about to come to an end. Several years of long stretches of days without sunspots (up to 125 days so far this year – 38 of the past 41 days have been spotless) indicate the imminent beginning of a new cycle.

Crews have been selected for the first commercial craft test flights and missions – Seven men, 2 women will crew flights beginning next year, 2019. Most notable is Philadelphia native Chris Ferguson, commander of the last space shuttle flight STS-135. He’ll be part of the Boeing CST-100 Starliner first flight as he’s been the development lead at Boeing since he retired from NASA after the last shuttle flight. The test flights will be followed by operational missions to ISS carrying both America and international astronauts.

Sunrise was 6:10am and sunset today is at 8 p.m. We’ve lost 1 hour 11 minutes of day length since June 21st and we’ll continue to lose 2 minutes/day until mid-November when we slow towards Winter Solstice.

Lastly, weather permitting – there’s an Astronomer Star Party at Strathmere Beach, New Jersey on Friday, Aug. 17th.

Mars’ close approach is Tuesday, July 31. A large subglacial lake of (very salty) liquid water has been found on Mars. This conclusion was arrived at by a group of European researchers using a radar analysis method frequently applied on Earth to determine subglacial features, including the presence of subglacial lakes.

Scientists have discovered 12 more of Jupiter’s moons, bringing the planet’s total count to 79. There are 175 known moons in the solar system overall, including Earth’s, Mars (2), Jupiter (79), Saturn (53), Uranus (27), and Neptune (13).

Follow a replay of the NASA lunar exploration events from 49 years ago online. http://www.firstmenonthemoon.com/ replays the actual audio communications between ground control and the astronauts from about 15 minutes before landing.

New studies based in data collected by the New Horizons spacecraft that flew by Pluto two summers ago suggest one scenario for Pluto’s creation could be the coalescence of a billion comets. Pluto is the largest object in the Kuiper Belt – a ring of icy objects orbiting around the sun, beyond Neptune. This idea was prompted by the amount of nitrogen ice observed at the left lobe of the heart-shaped region on Pluto’s surface. Much more work has to be done, but this possibility indicates Pluto’s origin is a much more complex story than originally imagined.

The moon slides through Venus July 15, Jupiter July 20, Saturn July 24, Mars July 27.

Japan’s Hayabusa 2 spacecraft arrives at asteroid Ryugu on Wednesday, beginning a string of encounters including fly-bys, landings (3 rovers and a lander!!), sample acquisition and Earth return. Hayabusa 2 left Earth in 2014 and traveled 180 million miles to catch the 3,000 foot wide asteroid.

This object is a member of the carbon-rich C-type asteroid family. Scientists believe these objects contain material that has remained undisturbed since the formation of the solar system. Thus, it’s something scientists would really like to study when it hasn’t been super-heated while falling to Earth.

JAXA plans to take high-resolution photos and gravitational readings over the coming months. After charting the surface, Hayabusa 2 will attempt as many as three brief landings. The team hopes to collect at least one gram of material from the surface of Ryugu. The first attempt will occur in October of this year, and another could happen as soon as February 2019. Hayabusa 2 also carries a small impactor, which should be able to produce a crater. The team may choose to land a third time inside that crater to collect a sample.

Analysis of stars seen beyond what was thought to be the edge of our Milky Way show a chemical composition strikingly similar to that of stars within the galaxy.

Independence Day is sandwiched between the start of the dog days of summer and Aphelion.

The dog days of summer are traditionally the 40 days beginning July 3 and ending August 11 (according to the Old Farmer’s Almanac), which coincide with the morning rise of the Dog Star, Sirius. Ancient Egyptians thought that the “combined heat” of Sirius and the Sun caused summer’s swelter.

Thursday July 5th is Aphelion, when the Earth at its most distant point from the Sun for the year; 94,508,060 miles. Our average distance from the Sun is 92,955,696 million miles.

4th of July Anniversaries:

In 1868 on July 4, Henrietta Leavitt born. Her discovery of the period/luminosity relationship discovery made it possible for Hubble to determine that the universe is expanding.

And for those who are suffering in this summer weather: Be glad you don’t live on Mars, which is currently experiencing a planet-wide dust storm.

Planets available to be seen in the night sky this week; 9:15p, Venus-west, Jupiter-south, Saturn-east, Mars:11:30-East.

Dave Heller and Derrick Pitts, chief astronomer at the Franklin Institute, discuss efforts to peer all the way back in time and space with:

They are in Philadelphia for a meeting at the University of Pennsylvania with the Simons Observatory regarding the Atacama Cosmology Telescope.

Image: M. Devlin. (M. Devlin, University of Pennsylvania) [CC BY-SA 4.0], via Wikimedia Commons

Daylight lasts 14 hours and 52 minutes now, and the rate at which we’re gaining daylight is slowing dramatically. The rate at which we gain daylight slows about 3 seconds per day so by the 21st, we’re at zero gain. The mechanics? We’re slowly coming to a point in our solar orbit where the North pole of Earth has its greatest degree of tilt toward the sun. This gives Northern hemisphere-dwellers our ‘longest’ day because the sun’s path travels its longest arc across the sky. On that day, the sun reaches its highest noon point. If you lived near George Town on Exuma in the Bahamas, on June 21, the sun would be directly overhead at noon. A great circle around the globe connects all points where the sun would appear overhead at noon on that day. The next day June 22, we lose 3 seconds of daylight here at our latitude near Philadelphia. We can talk about approaching mid-summer next week as we approach the solstice.

In our solar system, 175 moons orbit 8 planets. Researchers from UC Riverside and the University of Queensland have identified 121 exoplanets that have orbits in their star’s habitable zone that could have large enough moons that might be capable of supporting life.

Venus and Jupiter are visible just after sunset. Mars and Saturn appear just after midnight. Saturn hangs right above Sagittarius.

An especially carnivorous supermassive black hole sitting at the center of a galaxy is gobbling galactic gases at an astonishing rate – one solar mass every two days. The radiation released is so intense that if this object sat at the center of our galaxy, 65,000 light years away, the x-rays it generates would sterilize our planet, making life impossible.

Let’s talk about mass – the amount of matter in an object;