September 21, 2017

Astro-Challenge: Spot a “Dark Asteroid.”

The path of 10 Hygiea during the month of May 2011.

(Created by the Author in Starry Night & Paint).

This week, the planetary conjunctions continue in the dawn skies, one of the better southern hemisphere meteor showers revs up, and we’ll turn you attention to an asteroid you’ve never heard of, but should have. [Read more...]

Astro-Challenge: Can You Spot the Moons of Mars?

Mars and its moons as they appeared on the moment of their discovery in 1877. (Credit: Constructed by the Author in Starry Night).

Mars and its moons as they appeared on the moment of their discovery in 1877. (Credit: Constructed by the Author in Starry Night).

This weeks’ challenge is a toughie and not for the faint of eye sight. In 1877, American astronomer Asaph Hall discovered the Martian Moons using the newly installed 26” refracting telescope at the U.S. Naval Observatory. Named appropriately Phobos (fear) and Deimos (terror), the moons were well suited companions for Mars, the god of war. Both moons, however, are tiny; outermost Deimos is 12.6 km in size and orbits Mars once every 30.35 hours, while innermost Phobos is larger, at 22.2 km in size and orbits the Red Planet in only 7.7 hours! In fact, at an orbital radius of only 9,377 km, Phobos orbits its primary closer than any other satellite in the solar system. Both tiny misshapen worlds are believed to be captured asteroids that will, one day millions of years in the future, spiral into Mars. Most of the time, these moons lie out of the range of all but the largest telescopes; but as Mars just passed opposition this past week, however, sighting these elusive moons might just be possible. [Read more...]

An Ephemeris of the Martian Moons.

This is a quick posting of the best apparitions of the moon of Mars, Deimos and Phobos, as promised in the Mars opposition post. The tables run for a week after opposition, and are accurate to about 10 minutes or so. I hand crafted these in Starry Night after I found a lack of info about the web for this data. Obivously, we here at Astroguyz see a definite gap that those looking to spot these ellusive beasties are in need of. With Mars at opposition, the closest Full Moon of the year, and two back to back launches, its going to be a busy last week of January…. we’ll have a larger post out on tips to spy the Martian moons this weekend!

Deimos Date EST
     
Eastern Elongation 29 6:48
Western Elongation   21:33
Eastern Elongation 30 13:01
Western Elongation 31 4:00
Eastern Elongation   19:29
Western Elongation 1 10:42
Eastern Elongation 2 1:36
Western Elongation   16:22
Eastern Elongation 3 8:04
Western Elongation   22:30
Eastern Elongation 4 14:08
Western Elongation 5 5:31
Eastern Elongation   20:07
Western Elongation 6 11:20

 

Phobos

   
   Date  EST
Eastern Elongation 29 2:48
Western Elongation   6:46
Eastern Elongation   10:29
Western Elongation   14:19
Eastern Elongation   18:13
Western Elongation   21:48
Eastern Elongation 30 1:43
Western Elongation   5:37
Eastern Elongation   9:30
Western Elongation   13:10
Eastern Elongation   17:00
Western Elongation   20:55
Eastern Elongation 31 0:49
Western Elongation   4:41
Eastern Elongation   8:30
Western Elongation   12:04
Eastern Elongation   15:56
Western Elongation   19:45
Eastern Elongation   23:42
Western Elongation 1 3:30
Eastern Elongation   7:28
Western Elongation   11:10
Eastern Elongation   14:52
Western Elongation   18:47
Eastern Elongation   22:41
Western Elongation 2 2:34
Eastern Elongation   6:30
Western Elongation   10:19
Eastern Elongation   14:00
Western Elongation   17:45
Eastern Elongation   21:40
Western Elongation 3 1:30
Eastern Elongation   5:24
Western Elongation   9:11
Eastern Elongation   12:56
Western Elongation   16:42
Eastern Elongation   20:31
Western Elongation 4 12:29
Eastern Elongation   4:20
Western Elongation   8:08
Eastern Elongation   11:52
Western Elongation   15:41
Eastern Elongation   19:30
Western Elongation   23:10
Eastern Elongation 5 3:08
Western Elongation   6:58
Eastern Elongation   10:50
Western Elongation   14:40
Eastern Elongation   18:24
Western Elongation   22:10
Eastern Elongation 6 2:05
Western Elongation   6:01
Eastern Elongation   9:42
Western Elongation   13:42
Eastern Elongation   17:26
Western Elongation   21:08

Astro-Event: Mars at Opposition.

Mars during the 2005 opposition. (Photo by Author and Graphic created in Mars Previewer).

Mars during the 2005 opposition. (Photo by Author and graphic created in Mars Previewer).

Contrary to the once-every-August viral emails soon to be clogging your inbox, Mars will not appear as “large as a Full Moon” on this or any other year… but Mars will reach opposition this week on Friday, January 29th. Unfortunately, this apparition isn’t a particularly favorable one; Mars will only reach 14.1” arc seconds in apparent diameter, a far cry from the excellent 2003 opposition where it reached 25.1”, very close to the possible max. This is due to the fact that while Earth reached perihelion earlier this month, Mars is also very close to aphelion in its relatively eccentric orbit. In fact, although Mars approaches us every two years or so, the next really good opposition won’t be until 2018 (24.3”).  Still, any opposition of the Red Planet is worth viewing, as it is rare that Mars reveals any detail at all! Mars is currently in the constellation Cancer, and rises low in the east after sunset. Shining at magnitude -1.2, Mars is unmistakable for its orange-to red glow. Do things look a bit yellowish? A planet wide dust storm could be underway, as it is entering spring on the northern hemisphere of Mars. [Read more...]

Hailing Phoenix.

The receding ice in the region of the Phoenix Lander as seen from HiRise. (Credit:NASA/JPL/Caltech/Texas A&M University.

The receding ice in the region of the Phoenix Lander as seen from HiRise. (Credit:NASA/JPL/Caltech/Texas A&M University.

This week, engineers at NASA’s Jet Propulsion Laboratory will begin listening for a very special phone call; that of the Phoenix Lander on the northern polar region of Mars. Spring is in the air on the northern hemisphere of Mars, and bets are on as to whether the Lander survived the bleak Martian winter. Already, the outlook isn’t stellar; Phoenix has more than likely been encased in CO2 ice for several months; and don’t forget, the Martian year and seasons are roughly twice as long as here on Earth! Add to the fact the Mars is close to aphelion in its relatively eccentric orbit, and the odds don’t look good.  To phone home, Phoenix will need to recharge its spent batteries to a point where its automated broadcasting can kick in; the solar angle is currently about the same as when scientists lost contact last year. If it does start transmitting, Mars Odyssey currently in orbit will be listening. Odyssey passes over the landing site about 10 times a day, and will listen in over the next few months.  The sixth successful landing on the Red Planet and only the third successful soft landing, Phoenix returned some first rate science, and gave us concrete evidence of water ice lurking just below the Martian soil. Now approaching opposition, Mars is rising low in the east just after dusk; more on that next week! For now, Let’s hope that Phoenix lives up to its namesake and rises from the dead!

AstroEvent of the Week: October 27th- November 2nd; A Halloween Asteroid.

This Halloween brings a chance to spot one of the brightest known asteroids. 4 Vesta is currently placed in the constellation Cetus, the Whale and will be in opposition on October 29th this year, and thus be visible in moonless skies nearly all night.

[Read more...]

AstroEvent of the Week:29th-September 5th, 2008: Spot Neptune!

Now, to spot a planet that was first located mathimatically.

Now that the Moon is out of the sky this week, it’s a good time to add the outer most gas giant to your “been there, done that” list! First spotted in 1846 by Johann Galle & Heinrich D’Arrest, Neptune’s position was first deduced by the French Mathematician Le Verrier, who himself hated the “grittiness” of rank and file observational astronomy. [Read more...]