Dudley Observatory

This is Dudley Observatory’s Skywatch Line for Friday, October 30, through Sunday, November 1, written by Sam Salem. On Friday, Sun rises at 7:28am and sets at 5:50pm; Moon sets at 6:16am and rises at 5:46pm. Daylight saving time ends on Sunday at 2:00am. Moon reaches apogee, the farthest point from Earth in its orbit, at 2:45pm on Friday. It will then sit 252,522 miles from Earth. Full Moon occurs on Saturday, at 10:49am. This full Moon will occur only 20 hours after rea...Continue reading

This is the Dudley Observatory Skywatch Line for Wednesday, October 28th, and Thursday, October 29th, written by Louis Suarato. The 93% illuminated, waxing gibbous Moon rises at 5:05 p.m. Wednesday. Mars rises 4 minutes later and will trail the Moon by about 10 degrees throughout the night. Thursday night, Mars will lead the Moon across the sky. The Moon and red planet will be separated by about 5 degrees. Jupiter and Saturn emerge over the southern horizon 6 degrees apart d...uring twilight. The two gas giants will set at 10:28 p.m., and 10:55 p.m., respectively. Venus rises at 4:22 a.m., about 3 hours before sunrise. On October 28, 1991, Galileo became the first spacecraft to approach an asteroid. Galileo flew by the asteroid Gaspra on its way to Jupiter. Gaspra was discovered by Russian astronaut G.N. Neujmin in 1916. Gaspra is a 3.1 by 4.3 mile asteroid that completes its orbit around the Sun once every 3.29 years. Its orbit takes Gaspra beyond Mars to the asteroid belt, approximately 2.21astronomical units, or 205.53 million miles. Since then, 16 asteroids have been visited by space probes. The most recent mission to an asteroid occurred last week when the spacecraft OSIRIS-Rex (Origins, Spectral Interpretation, Resource Identification, Security Regolith Explorer) landed on asteroid 101955 Bennu and obtained samples. After traveling over 200 million miles in four years, OSIRIS-Rex collected a sample of about 60 grams from the asteroid’s surface. The sample will be returned to Earth in September 2023. Asteroid Bennu was chosen for this mission because it is composed of carbon rich materials carrying the building blocks of planets and life and may shed light as to how the solar system was formed. Bennu orbits the Sun once every 1.2 years, coming as close as 300,000 miles to Earth.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, October 26th, and 27th, written by Joe Slomka. The Sun sets at 5:55 PM; night falls at 7:30. Dawn begins at 5:49 AM and ends with the Sun rising at 7:24. The constellation Aquarius hosts the Moon on both nights. Monday’s 13-day-old Moon rises at 4:18 PM, 30 arc-minutes in size and appears 82% illuminated; it sets at 3:15 AM. Tuesday’sMoon is slightly smaller, but 88% lit, rises at 4:42 PM and sets at 4:16 AM...Continue reading

This is Dudley Observatory’s Skywatch Line for Friday, October 23, through Sunday, October 25, written by Sam Salem. On Friday, Sun rises at 7:19am and sets at 6:00pm; Moon rises at 2:43pm. Moon completes the first quarter of its orbit around Earth at 9:23am on Friday. The evenings surrounding first quarter are the best ones to see the lunar terrain when it is dramatically lit by low-angled sunlight. For a few hours near its first quarter phase, a feature on the Moon calle...Continue reading

Don't forget to look to look in your night sky for Pegasus, one of the most prominent constellations of Autumn that can be found west of Mars. This is the seventh largest constellation and can be identified by four stars making up the Great Square of Pegasus. As these stars are located in a relative empty sky void of bright stars, they are easier to see. Shown below is the M15 globular cluster located in Pegasus (visible with binoculars appearing like a fuzzy star). Image credit: ESA, Hubble, NASA

Did you miss our September Octagon Barn with Tom Donlon (Renesslaer Polytechnic Institute) on "The Milky Way is a Cannibal"? The Albany Times Union provides a fantastic overview of the evidence he and our Board President, Dr. Heidi Jo Newberg have discovered of a collision between the Milky Way and a smaller dwarf galaxy over 3 billion years ago. Congrats on the great work!... Sign up for our newsletter on dudleyobservatory.org to be notified of upcoming Octagon Barn lectures. https://www.timesunion.com//RPI-astrophysicists-find-evide

This is the Dudley Observatory Skywatch Line for Wednesday, October 21st, and Thursday, October 22nd, written by Louis Suarato. Look over the south-southwestern horizon after sunset on Wednesday for the 33% illuminated, waxing crescent Moon. To the Moon’s upper left are Jupiter and Saturn. Thursday night, the nearly First Quarter Moon moves below the 2 gas giants to form a triangle. Saturn and Jupiter are 6 degrees apart. In the east, Mars shines at magnitude -2.45 after risi...ng at 5:43 p.m., Wednesday. Thursday night, all four Galileo moons will be visible to the sides of the Jupiter until Io begins to transit the planet at 11:30 p.m.. Jupiter’s Great Red Spot begins its transit across the central meridian at 8:31 p.m., Wednesday. Venus rises in the constellation Virgo at 4:07 a.m. Thursday. Look to the west of Mars for one of the most prominent constellations of Autumn. Easily identified by its Great Square asterism, Pegasus is the seventh largest constellation. The four stars that comprise the Great Square of Pegasus are located in a relative empty sky, void of bright stars, so are easy to see. The four bright stars are Alpheratz, the upper left star in the square in the northeastern corner and actually part of the constellation Andromeda. Markab is located at the southwestern corner of the Square. Algenib is located at the southeastern corner. Scheat is at the northwestern corner and is a bright giant red star visible through binoculars. Algenib is located at the southeastern corner of the Great Square. Algenib is located 335 light-years away and is the dimmest of the four stars. M15 is a globular cluster located in Pegasus. Discovered by Jean-Dominique Maraldi in 1746, M15 shines at magnitude 6.4 and is 33,600 light-years from Earth. It is one of the oldest known globular clusters, estimated to be 12 billion years old. M15 is one of the most densely packed globular clusters in the Milky Way, comprised of over 100,000 stars. In 1928, a planetary nebula known as Pease 1, was discovered by Francis G. Pease at the center of M15. Only telescopes with an aperture of 12 inches or more can detect Pease 1. Look for M15 4 degrees to the northwest of the star Enif, the brightest star in the constellation.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, October 19th, and 20th, written by Joe Slomka. The Sun sets at 6:06 PM; night falls at 7:40. Dawn begins at 5:40 AM and ends with the Sun rising at 7:15. The Moon resides in the constellation Ophiuchus each night. Monday’s Moon rose in daylight and sets at 8:16 PM. The planet Mercury is tonight’s challenge object, because it is close to the Moon and sets at 6:47 PM. Observers are advised to avoid looking at ...the Sun. Monday’s Moon also shines above Antares, the main star in Scorpius. Tuesday’s Moon appears 34 arc-seconds in size, 24% illuminated and sets at 9:03 PM. Sagittarius continues to show Jupiter, Pluto and Saturn. Jupiter rises at 2:19 PM, shines with minus 2nd magnitude, appears 38 arc-seconds, is best observed at 6:48 PM and sets at 11:17 PM. Tuesday, sky watchers can witness the Jovian moon Europa begin to crawl across the planet’ face at 7:14 PM, followed by its shadow at 9:49 PM, Europa exits at 10:02 PM. Pluto is found between Jupiter and Saturn, glowing with 14th magnitude, appears as a tiny dot, rises at 7:04 PM and sets at 11:32 PM. Six degrees East of Jupiter, Saturn rises at 7:16 PM, shines with zero magnitude, appears about 17 arc-seconds and sets at 11:51 PM. Both Jupiter and Saturn are still worth observing, but are now daily setting earlier. Neptune, in Aquarius, rises at 5:08 PM, shines with 7th magnitude but appears only 2 arc-seconds big; highest at 10:46 PM, it sets at 4:28 AM. Uranus, in Aries, rises at 7:01 PM, glows with 5th magnitude, appears 3 arc-seconds. Best seen at 1:58 AM it sets in daytime. Mars, in Pisces, flashes with minus 2nd magnitude and appears 22 arc-seconds. Rising at 6:30 PM, it is best surveyed at 12:54 AM and sets in daytime. Now past Opposition, Mars starts to move away from Earth and appears slightly smaller and dimmer daily. Venus brings up the rear, rising in Leo at 3:50 AM, blazing with minus 4th magnitude, almost 15 arc-seconds and 78% illuminated. Venus sets during daytime. Pre-dawn observers on Tuesday and Wednesday nights may see meteors streaming from the area of Orion's club. This is the annual Orionid meteor shower. Meteor showers result when Earth's orbit crosses paths with debris from comets’ tails. The Orionids come from the most famous comet of them all - Comet Halley, which returns about every 76 years. Astronomers predict an average year for the Orionids. The shower’s peak is Wednesday. The constellation is high and the Moon sets before 10 PM. If observing conditions are good, one may see up to 15 meteors per hour. The observer needs no special equipment; he simply stares at the sky. Since this is Autumn, cold weather clothing and boots help avoid the chill.

Try to spot Uranus unaided this weekend. Uranus found in constellation Aries, is well up in the east by 10pm, about 18 degrees east of Mars. Uranus is only 3.7 arcseconds wide, but that's enough to appear as a tiny fuzzy ball, not a point, at high power in even a small telescope. Image credit: NASA/JPL. Uranus as seen by NASA's Voyager 2 in 1986.

Congratulations to Astrophysicist Andrea Ghez (UCLA) who has been awarded the 2020 Nobel Prize in Physics for her work with a supermassive black hole in the middle of the Milky Way galaxy. To learn more about women in science, please join us tonight for our Octagon Barn presentation with Dr. Cecilia Levy on becoming a woman physicist and the amazing journey to explore the universe. Email us at [email protected] to be added to the mailing list for tonight's zoom link.... Image Credit: NASA/Chandra X-Ray Observatory

This is Dudley Observatory’s Skywatch Line for Friday, October 16, through Sunday, October 18, written by Sam Salem. On Friday, Sun rises at 7:10am and sets at 6:10pm; Moon rises at 6:40am and sets at 6:30pm. New Moon occurs on Friday at 3:31pm. New Moon travels between Earth and the Sun. New Moons travel across the sky with the Sun all day, lost in the sun’s glare. This new Moon occurs only 4.5 hours after perigee, the Moon’s closest approach to Earth, triggering large tid...Continue reading

Please join us this week for our next Octagon Barn lecture on Friday, October 16, 2020 at 7pm. Dr. Cecilia Levy, Assistant Professor of Physics at University at Albany, SUNY will be presenting her talk "Becoming a Woman Physicist: The Amazing Journey to Explore the Universe. And a lot of Challenges". To receive reminders of upcoming Octagon Barn lectures and their zoom links, please head to dudleyobservatory.org to sign up for our newsletter.... Image: Dudley Observatory Dedication, August 28, 1856. Oil on canvas by Tompkins H. Matteson (1813-1884). (Look for Blandina Bleeker Dudley, widow of Charles Edward Dudley, for whom the observatory was named sitting on the left in a lavender gown.)

This is the Dudley Observatory Skywatch Line for Wednesday, October 14th, and Thursday, October 15th, written by Louis Suarato. The 5% illuminated, waning crescent Moon sets at 5:36 p.m. Wednesday. Look for the Moon as a 3% illuminated crescent Thursday in the pre-dawn sky below Venus. For the next two weeks, look for the zodiacal light in the east before sunrise. The zodiacal light is comprised of interplanetary dust particles illuminated by the Sun. this conical shaped ligh...t can be seen through the end of the month. Mars, one day past its opposition, glows at magnitude -2.61, above the eastern horizon after sunset. Mars remains in the sky the entire night. While Mars is rising in the east, Saturn and Jupiter will be high over the southern horizon, 6.5 degree apart. The two gas giants will set before midnight. Take advantage of these moonless nights to get a good view of M31, the Andromeda Galaxy. Our closest large neighboring galaxy will be about 50 degrees above the east-northeastern horizon after 8 pm. Use Cassiopeia’s deeper V to point the way 15 degrees to Andromeda. M31 is 2.5 million light-years from Earth, and 220,000 light-years wide. The Milky Way is estimated to be 105,000 light-years wide. The Andromeda Galaxy is estimated to contain over 1 trillion stars, compared to the Milky Way’s estimated 200 billion stars. Andromeda is categorized as a barred spiral galaxy. Its center is dissected by a central bar of bright stars. Look about 12 degrees below the Andromeda Galaxy for M33, the Pinwheel or Triangulum Galaxy. Along with the Milky Way and the Andromeda Galaxy, the Triangulum Galaxy is part of what is known as the Local Group. The Local Group is made up of 54 galaxies, most of them dwarf galaxies. The gravitational center is somewhere between Andromeda and the Milky Way. M33is also a barred spiral galaxy, and is about 60,000 light-years wide and contains approximately 40 billion stars. At 2.7 million light-years away, the Triangulum Galaxy is a bit farther away than the Andromeda Galaxy. The Triangulum Galaxy is speeding toward the Milky Way at 180 miles per second. Data obtained from the European Space Agency’s Gaia mission suggest that the Triangulum Galaxy is either on a billion year orbit around Andromeda, and may have fallen into it in the past, or is on its first in-fall.

This is the Dudley Observatory Skywatch Line for Monday, Columbus Day, and Tuesday, October 12th and 13, written by Joe Slomka. The Sun sets at 6:17 PM, night falls at 7:51. Dawn begins at 5:33 AM and ends with the Sun rising at 7:07. The Moon resides in Leo on both nights. Monday’s Moon sets at 4:30 PM. Tuesday, the 25-day-old Moon rises at 2:47 AM, 17% illuminated, 32 arc-minutes in diameter and sets at 5:03 PM. Tuesday’s Moon appears besides Leo’s brightest star, Regulus, ...Continue reading