9:30 AM | Perseid meteor shower peaks late Wednesday night and it could be a great show this year

[Image of Perseid meteor over China from 2013]

Discussion

The Perseid meteor shower that arrives this time every year should be particularly spectacular when it peaks overnight Wednesday as the moon will be in its darkest or “new” phase. Up to 100 shooting stars per hour will streak across the sky during the peak and - given the lack of interference by moonlight – this could result in a stellar show as long as sky conditions are favorable (and they should be).

The Perseid meteor shower occurs every year from mid-July to mid-August as the Earth passes through a cloud of dust that comes from Comet Swift-Tuttle as it approaches the sun. Earth's gravity pulls in some of the chunks of debris — small rocks comprised of iron-nickel, stone, other minerals or a combination of these — which turn into bright balls of hot gas when entering Earth's atmosphere. Typically, the meteors are only the size of pebbles, some as small as a grain of sand. As darkness falls, the meteors appear to come from the constellation Perseus, hence the name; although late in the evening, the meteors originate higher in the sky than the constellation.

Perseid meteoroids hit our atmosphere at ~132,000 mph to produce the annual light show and this particular meteor shower is usually rich in “fireballs” because of the size of the parent comet. Comet Swift-Tuttle has a huge nucleus – about 26 kilometers in diameter whereas most other comets are much smaller with nuclei only a few kilometers across. As a result, Comet Swift-Tuttle produces a large number of meteoroids, many of which are large enough to produce fireballs. In fact, the Perseid meteor shower is considered the “fireball champion” of all of the annual meteor showers.

The best time to look during the peak is between the hours of 11pm (Wednesday night) and 5am (Thursday morning) far away from city lights.

11:15 AM | Amazing close-up view of Pluto and now all nine "planets"

[Final color image of Pluto before the flyby; courtesy NASA]

Discussion

NASA’s New Horizons spacecraft has made the first ever visit to Pluto speeding past at 30,000 miles per hour. This image (above) was taken late yesterday and is the final color image taken just before the flyby from about 476,000 miles away. In the image, we can see the "heart" of Pluto in much greater detail than before, craters that were impossible to make out in previous images, and a great view of the dwarf planet's dark equatorial belt. There are more images of the face of Pluto to come. The first true high-resolution mosaic image will be released tomorrow afternoon, and a few more will be released throughout the week. A much larger set will be released starting in September.

With this close-up view of Pluto that was more than nine years in the making, all nine objects considered by many to the solar system’s planets – from Mercury through Pluto – have now been visited at least once by a probe. This image below features some of the best available viewpoints of all nine planets in the solar system including the very latest of the dwarf planet Pluto (lower right).

[All nine planets in our solar systems have now been visited at least once by a probe]

One of the interesting findings regarding Pluto based on this close-up view is that the dwarf planet is apparently a bit bigger than previously thought. The diameter of Pluto will be increased by about 20 or 30 miles based on the new data according to NASA scientists. Also, early interpretation of the data suggests Pluto has “a history of impacts” and “surface activity that may be interpreted as tectonic indicating internal activity in the past and perhaps even in its present”. Pluto is quite unusual in that it is a fraction of the size of the Earth and yet has five moons. The dwarf planet slightly orbits the largest moon, Charon, leading some to suggest that the pair could be best described as a double planet system. Charon is about 750 miles across and half the diameter of Pluto – making it the solar system’s largest moon relative to its planet.

2:45 PM | We've never seen Pluto close up...until now

[Image of Pluto taken by NASA's New Horizons spacecraft on July 7th; courtesy NASA]

Discussion

It took NASA’s New Horizons spacecraft nine years to cover the 3 billion mile trip there, but come next Tuesday, July 14th, it’ll fly within 7,750 miles of Pluto and show us the dwarf planet and its five moons for the first time. Pluto is the farthest destination for any space mission in history and because New Horizons is traveling at such a high speed (~31,000 miles per hour) and can’t slow down, the flyby will be over in a matter of minutes. This brief encounter with Pluto will mark the first time since 1989 – when Voyager 2 probe fled by Neptune – that we’ll be seeing an entirely new world for the first time. Not even the Hubble Space Telescope could see the dwarf planet clearly, but those days are over.

In fact, over the past few weeks New Horizons has closed in on Pluto giving us better and better photos including the one above taken on July 7th from about 5 million miles away. While this photo is a big improvement from anything captured beforehand, it is nothing compared to what will come later next week after closest approach. The images taken at closest approach next Tuesday will actually not be available for viewing until a couple of days later (7/16), and they are expected to reveal high-resolution geological features on the surface of Pluto. They could reveal mountains, ice caps, volcanoes, or even an ocean of liquid water under ice – nobody knows for sure.

Pluto is quite unusual in that it is a fraction of the size of the Earth and yet has five moons. The dwarf planet slightly orbits the largest moon, Charon, leading some to suggest that the pair could be best described as a double planet system. Charon is about 750 miles across and half the diameter of Pluto – making it the solar system’s largest moon relative to its planet. Three of the smaller moons are swept up in the pair’s gravitational field which leads to bizarre and chaotic orbits of their own.

9:45 AM | Saturn is worth a look now as its rings surge in brightness

[This is an animation of two Saturn images about 10 minutes apart using a 16-inch telescope. It shows gaps in Saturn's rings, clouds in the planet's atmosphere, and a famous hex-shaped storm around Saturn's north pole. Courtesy "spaceweather.com"]

Discussion

If you have a backyard telescope then the best time to see the planet Saturn in 2015 is here! Saturn’s rings will surge in brightness tonight as the planet will be at “opposition” – that is, opposite the sun. The Earth passes in between Saturn and the sun later tonight and the ringed planet will be at its closest to the Earth and brightest in our sky. Saturn will rise in the eastern sky at sunset (opposite the setting sun) and then move through the southern sky reaching its highest point at midnight in the region of the constellation Scorpius (see sky map). Saturn should shine a touch brighter than Antares, the brightest star in the constellation Scorpius. Saturn will then set in the western sky at sunrise.

[An "opposition" takes place when Earth goes between Saturn and the sun]

Whenever Saturn is at “opposition”, its rings surge in brightness. Saturn’s rings are made of frozen chunks of ice ranging in size from dust to houses. Sunlight backscattered from these ice particles cause the ring system to shine more than usual around “opposition”. This is not a one-time event. Saturn’s rings should be in good view through June 2015, and it will remain a fixture in the evening sky until the fall. Skies should clear tonight following the passage of a cold frontal system – but it will get quite cold. Skies have a good chance of being clear tomorrow night as well.

8:45 AM | Lyrid meteor shower peaks late tonight

Discussion

Earth is entering a stream of debris from Comet Thatcher, the source of the annual Lyrid meteor shower. This particular meteor shower has been seen each April for more than 2600 years making it one of the oldest known meteor showers. If forecasters are correct, April’s top meteor shower will peak late tonight with 10 to 20 meteors visible per hour. The best time to look for the meteors is between about 11 pm and sunrise on Thursday. Skies should clear somewhat by late tonight in the Mid-Atlantic region following the passage of a strong cold frontal system allowing for possible viewing of the meteor shower.

The Lyrids are quite unpredictable and have a history of putting on surprising performances. In 1982 and way back in 1922, the shower delivered a reported 90 meteors per hour. In 2014, the Lyrids were hampered in part due to moonlight from the last-quarter moon, but that won't be the case this year. This year the moon will be a waxing crescent - only one-fifteenth the brightness of a full moon - and it will set early allowing for excellent dark sky conditions for this shower. Typically, Lyrids produce a gratifying number of fireballs, which is somewhat surprising since their relatively moderate speeds of 30 miles per second is only about 75 percent that of the August Perseids or November Leonids. The Lyrids radiant point is about 10 degrees southwest of the blue-white star Vega (see sky map above). The Lyrid meteor shower lasts from roughly April 16-26 each year, but it is best seen on only about two nights.

1:50 PM | Strong geomagnetic storm currently underway and it could cause northern lights into this evening...Friday will feature three celestial events

[Northern lights seen earlier today in northern Alaska; courtesy spaceweather.com]

Discussion

Northern Lights and an ongoing geomagnetic storm

Despite an overall quiet look to the sun, a coronal mass ejection (CME) hit the earth’s magnetic field earlier today sparking bright auroras across many northern latitude locations around the world including the northern tier of the US. The sun is currently featuring just one noticeable sunspot region (circled area) and it is from here that the current geomagnetic storm originated. At first, the impact generated a relatively mild "G1-class" geomagnetic field, but then it intensified into a “G4-class” ranking it as the strongest geomagnetic storm of the current solar cycle (#24).

[Current image of the sun with sunspot region circled; courtesy spaceweather.com]

This storm could continue for many hours to come as the earth passes through the turbulent wake of the CME. Should the storm continue at its current intensity into the evening hours, northern lights could even be visible (in dark areas) as far south as the I-95 corridor. Skies should clear out this evening in the I-95 corridor following an Arctic cold frontal passage.

Friday will feature three celestial events

There will be three celestial events this Friday including a total solar eclipse, a "new supermoon", and the spring equinox, but none of these will actually present anything visible around here. In fact, the total solar eclipse will be seen by very few people as it's visible path - while unusually wide and long - will mostly pass over the open North Atlantic Ocean. A Supermoon, or perigee moon, happens when the full or new moon does its closest fly-by of the Earth, making it look bigger than it normally does. There are actually six supermoons during 2015, but only three of them are visible during the full moon phase. The supermoon this Friday will not be visible as it will occur during the new moon phase. And the spring equinox refers to the time of the year when the day and night are of equal duration, mid-way between the longest and shortest days.

10:50 AM | An update on Comet Lovejoy...now in its best two weeks

[Image of Comet Lovejoy; courtesy Washington Post's Capital Weather Gang]

Discussion

Overview Comet Lovejoy, C/2014 Q2, is in the midst of its best two weeks. Comet Lovejoy is now about magnitude 3.8, and it should remain that bright all week. On January 7th the comet passed closest by Earth, at a distance of 0.47 a.u. (44 million miles; 70 million km). Although the comet is receding from us now, its intrinsic brightness should still be increasing a bit. That's because it doesn't reach perihelion (its closest to the Sun) until January 30th (at a rather distant 1.29 a.u. from the Sun). By that date, the comet should finally be fading slightly from Earth's point of view.

Where to look Comet Lovejoy is high in the early-evening sky for binoculars or low-power, wide-field telescope viewing. It's also dimly visible to the unaided eye under dark-sky conditions — if you know exactly where to look! According to the Washington Post’s Capital Weather Gang, you’ll find Comet Lovejoy high enough around 8 p.m. (and the later hours too) to the right of the constellation Orion and just under the constellation Taurus. Think of the three stars (Alnitak, Alnilam and Mintaka) of Orion’s belt as a pointer toward the comet, because if you look carefully in a very dark sky, you could see a faint glow. By Thursday, Friday and Saturday, the comet will pass to the right of the Pleiades cluster – also know as the Seven Sisters or Messier 45. Our original story on Comet Lovejoy with links to finder charts can be found at http://vencoreweather.com/2014/12/31/1000-am-comet-lovejoy-rings-in-the-new-year/. Skies may be clear this evening for comet viewing; however, clouds are likely to roll in from the south by late tonight.

[Finder chart for tonight, January 13th; map courtesy Andrew Ochadlick and heavens-above.com]

10:00 AM | Comet Lovejoy rings in the New Year!

[Image of Comet Lovejoy on 12/29/14; courtesy "spaceweather.com"]

Discussion

Comet Lovejoy is just now becoming visible to the naked eye in the northern hemisphere and it is expected to more than double in brightness by mid-January. Currently, the comet shines at magnitude +5.0 and can be seen in dark sky conditions as a fuzzy patch near Orion’s belt several hours after sunset. This is the fifth comet discovered by the Australian astronomer Terry Lovejoy – officially named C/2014 Q2 - and it will pass about 70 million kilometers (44 million miles) from the Earth on January 7th with its peak brightness expected to reach around 4th magnitude which should be pretty easily visible without any optical aid. The location of Comet Lovejoy will be a bonus as it should be relatively easy to find near the constellation of Orion. It’ll also glide past Taurus and the Pleiades over the next few weeks. The comet is moving to the north so it is getting higher all the time for Northern Hemisphere observers.

By January 7th – the time of closest approach – the nearly full moon will make it tougher to see, but after that the moon will rise late enough that it won’t be as big of a problem. In the photo (above) the comet-head appears green and the tail appears blue; however, those colors will likely not be apparent to the naked eye. These colors come from ionized carbon monoxide (CO+) and diatomic carbon (C2), which glow blue and green, respectively, in the near-vacuum of interplanetary space. Long exposure photography tends to bring out the green hue in the comet-head. As for the physical nature of the comet itself, it’s on a pretty long-period orbit, taking about 14,000 years to go around the Sun. The orbit takes it out to a distance of nearly 90 billion kilometers (for comparison, Neptune orbits at a distance of 4.5 billion kilometers).

Finder charts for January can be found here courtesy "Sky and Telescope": http://www.skyandtelescope.com/wp-content/uploads/Lovejoy2_BW.pdf Also, another web site that can help in the location of the comet can be found at http://heavens-above.com. Simply follow the instructions at this web site by entering your observing location under "Configuration" (Philadelphia is close enough for all of SE PA) and then enter Comet Lovejoy under "Astronomy" for a particular time.

10:45 AM | Spacecraft to land on comet early Wednesday after 10-year flight

PHOTO: Comet 67P/Churyumov-Gerasimenko is seen in a photo taken by the Rosetta spacecraft with the OSIRIS narrow-angle camera August 3, 2014.

Discussion

The European Space Agency’s (ESA) Rosetta spacecraft was launched in March 2004 and spent years in “hibernation” as it moved through some 4-billion miles of space at speeds as high as 84,000 mph on its way to a rendezvous with a comet officially known as “67P/Churyumov-Gerasimenko”. Since August of this year, the spacecraft has been orbiting the comet with its closest point being about 18 miles and has taken numerous images revealing steep ravines, sharp cliffs and numerous boulders. The scheduled touchdown on the comet of the mission’s Philae lander – about the size of a washing machine - is set for this Wednesday at 10:35AM EST and, if all goes well, it would be the first-ever soft landing of a spacecraft on a comet. The gravity of the comet is 60,000 times less than the gravity of Earth, and scientists expect it will take the lander seven hours to free-fall about 14 miles from its mother ship, Rosetta, to the comet. Then there is a delay of 28 minutes for a signal from Rosetta to reach our planet. This will indeed be a difficult landing as the comet will be moving 40 times faster than a speeding bullet.

After touchdown, the Philae lander will obtain the first images ever taken from a comet’s surface and will drill into the surface to study the composition. Philae can remain active on the surface for about two and a half days. The mothership Rosetta will remain in orbit around the comet through next year continuing to study the comet as it approaches the sun and then moves away. Comets hold vital clues about our solar system’s history and are considered primitive building blocks that are literally frozen in time. NASA has provided 3 of the 16 instruments on board the Rosetta orbiter.

NASA will provide live coverage of the landing at: http://www.ustream.tv/nasajpl2 or you can visit the ESA live streaming web site at http://new.livestream.com/ESA/cometlanding.

9:40 AM | Antares rocket explodes shortly after launch...two video viewpoints and an infrared imagery loop that shows the sudden warm spot

Discussion

The Antares rocket launch that was pushed off 24 hours by a boat in the safety zone region on Monday ended quickly last night in an explosion at the NASA/Wallops Island, Virginia facility. The unmanned commercial rocket which was headed for the International Space Station (ISS) to deliver 5,000 pounds of supplies and experiments blew up moments after liftoff on the Eastern Shore of Virginia creating a massive fireball. Fortunately, no injuries were reported on the ground. Officials from NASA and Orbital Sciences hope to find out what happened in the coming days by analyzing the data and debris that remains near the launch pad. The crew aboard the ISS is not lacking when it comes to supplies. They have food, water and other consumables necessary to support them well into next year. Here is video of the explosion from the official NASA feed http://www.youtube.com/watch?v=jHMmMgdcOSU and here is a video that was taken from 3000 feet (both courtesy YouTube) http://www.youtube.com/watch?v=ciGK9FqUqXw. Finally, the University of Wisconsin has put together an infrared imagery loop that shows a sudden warm spot at the time of the explosion (red circle): http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2014/10/141028_goes13_shortwave_ir_Wallops_rocket_explosion_anim.gif .