Animation of 2010 RF12 composed of 4 unfiltered exposures, 30-seconds each obtained by means of a 0.25-m, f/3.4 reflector + CCD - Credit: Ernesto Guido & Giovanni Sostero

According to the most recent orbital elements, 2010 RK53 passed the perigee of roughly 76,300km at around 23:30 UT on September 8. This time there was no “warning”. The object came in at an elongation of about 34 degrees, i.e. from the direction of the Sun in the sky, where no ground-based telescope can aim (and hope to get any useful results). Therefore, 2010 RK53 wasn’t observed up until it had already gone by. Nevertheless, unlike 2010 RX30 and 2010 RF12, which are now lost in sunlight (at elongation of less than 30 degrees), 2010 RK53 will remain observable by medium and large sized telescopes for a few days until September 13-14.

Although the object had no chance of hitting Earth, a ten meter-sized near-Earth asteroid from the undiscovered population of about 50 million would be expected to pass almost daily within a lunar distance, and one might strike Earth’s atmosphere about every ten years on average.

Courtesy of SOHO/STEREO consortium. SOHO is a project of international cooperation between ESA and NASA.

* Earth Crossers are Red, Earth Approachers (Perihelion less than 1.3AU) are Yellow, All Others are Green

Notice how the pattern of discovery follows the Earth around its orbit. Most discoveries are made in the region directly opposite the Sun, when asteroids are close to opposition. At the time of opposition Main Belt Asteroids are not only closest to Earth in their orbit around the Sun, but also most of their surface is illuminated (when seen from the Earth) and therefore they are reaching their maximum brightness.

Furthermore, you’ll also notice some clusters of discoveries on the line between Earth and Jupiter, these are the result of surveys looking for Jovian moons. Similar clusters of discoveries can be tied to the other outer planets, but those are not visible in this video.

As the video moves into the mid 1990′s we see much higher discovery rates as automated sky scanning systems come online. Most of the surveys are imaging the sky directly opposite the sun and you’ll see a region of high discovery rates aligned in this manner.

At the beginning of 2010 a new discovery pattern becomes evident, with discovery zones in a line perpendicular to the Sun-Earth vector. These new observations are the result of the WISE (Widefield Infrared Survey Explorer) which is a space mission that’s tasked with imaging the entire sky in infrared wavelengths.

Currently we have observed over half a million minor planets, and the discovery rates show no sign that we’re running out of undiscovered objects.

I have amassed a nice collection of sunrise photos, some of which have elements that are unique to this location, such as plumes from pre-dawn launches that resemble fire-breathing dragons. I am going to combine the best of these photos into a book, and then pepper it with little bits of historical information about the structures that appear in some of the photos.

The book funding project is hosted on The Kickstarter and at the time of writing the project had 72 backers who had pledged almost $5,000 (see the details below).

Kennedy Space Center Sunrises - A Photo Book

The best part is that you’ll get your money back in the form of an e-book. Those who donate ($50 or) more will receive a hard-copy signed by the same hand that signs shuttle banners. And, of course, the higher your pledge the better the goodies that come with the book.

To make a pledge, simply visit the project website. As a freebie you can have a look at Jen’s amazing sunrise photo collection on flickr

Spot of light - Credit: Jen Scheer

Meteorwatch 2010 Map

To report meteors and have them added to the map simply send a tweet in the form of:

#meteorwatch [postcode] [country] [meteor count]

e.g. #meteorwatch e15 uk 5

For more information about the valid format see the bottom of the map page.

After a tremendous success in 2009, the Twitter Meteorwatch will continue in 2010 with a few extra ways to participate. Apart from including #meteorwatch hash tag in your tweets, this year you will be able to add photos to the meteorwatch gallery* and see the meteor activity observed by other around the world using the meteorwatch map* (still under construction). Below is the long awaited Meteorwatch 2010 Trailer created by Adrian West / @VirtualAstro.

* … both of which are the reason I have not written a blog post in three weeks

Damian Peach, one of the most prominent planetary astrophotographers, assembled a sequence of his photos during the latest apparition of Mars into a video below. The video displays, in high definition, a full rotation of the Red Planet (24.622 hours).

Visit Damian’s webpage for more amazing astrophotography.

Despite having logged hours and hours of CCD data collection and reduction, Skymorph really helped me to get familiar with the latest tools (such as Astrometrica). I definitely recommend it to anyone wishing to start an astrometry program as you will learn the step-by-step process of using tools such as the MPC services, services from asteroid.lowell.edu, Astrometrica, etc. You’ll find new unknown objects and learn to distinguish them from false signatures; gain experience to follow up on your the discoveries (and even do precovery work) and learn to produce astrometry reports in the format accepted by the MPC.

My discovery of 2002 RO282 in NEAT/Skymorph data

In the 90′s and early years of the last decade, anyone with a medium-sized telescope and a CCD camera had pretty good chances to discover asteroids. Nevertheless, since NASA funded big surveys have started sweeping virtually the entire sky (visible from the northern hemisphere) every month, amateur discoveries require much bigger telescopes (0.5m and more) to allow one to reach beyond the 20th magnitude. A much cheaper alternative to owning a big telescope is to rent time on one. There are a few options out there, but I personally prefer the Lightbuckets remote observatory and the incredible 24″ Ritchey–Chrétien telescope from RC Optical Systems.

Lightbuckets LB-0001 - 0.61m (24") Ritchey-Chrétien

Located under the excellent northern hemisphere skies of southwestern New Mexico, LB-0001 equipped with Apogee Ulta 42 CCD camera (with quantum efficiency reaching staggering 90%) can easily reach beyond the 20th magnitude in a single 60s unfiltered exposure. The ability to observe objects fainter than 20th magnitude is crucial for minor planet hunting as the vast majority of brighter objects have already been found.

I discovered my first minor planet in the very first image set taken with LB-0001 (statistically, the odds of finding an object of ~21st magnitude in the 20′x20′ field of wiew of LB-0001 are pretty good). But the discovery of a minor planet is only the beginning. Further observations are necessary to determine the orbit well enough so that the object can be recovered at next opposition. This usually requires an arc of at least 2-3 weeks, but the longer the better.

The discovery animation of minor planet 239792. At the first measured position the object had brightness of V21.1, i.e. about million times fainter than one can see with a naked eye.

Once an object has been observed for 2 or more weeks, it is possible to search for identifications with previously-discovered provisionally-designated objects observed at only one opposition in the past. If an identification is made, one of the provisional designations is defined to be the principal designation. This is generally the earliest opposition at which a reasonable orbit was computed. An orbit is considered to be “reasonable” if it is good enough to use as a starting orbit to link the other observations.

Although numbering of a Main Belt asteroid usually requires observations from four oppositions (i.e. takes at least 4-5 years), with a good amount of luck your newly discovered object could be numbered within 1-2 months. If the observed arc from the current opposition can be used to link a few observations from the past, it is possible that the orbit will be refined well enough so that the object can be numbered. That is exactly the story of a minor planet (239792) 2010 EM34 I discovered using LB-0001.

2010 EM34 Discovery Astrometry

On March 9, 2010, during one of my regular searches in the area close to the ecliptic just before opposition, I noticed a previously unknown moving target. The data from the same night showed a few other brighter targets, so I did not select this object for a follow-up and reported it as a 1-nighter. Fortunately, the  Mt. Lemmon Survey (G96 ) swept the area of the sky into which my 1-nighter moved in 4 days and reported it to MPC. The processing routine determined that the two one-nighter observations belong to the same object and thus assigned it a provisional designation 2010 EM34.

2010 EM34 follow-up from March 21. The brighter minor planet close to the bottom is 171343.

After a week, on March 21, I observed the objects again extending the observed arc to 12 days. This follow-up observation was of a crucial importance. Thanks to the 12-day arc, MPC was able to link an observation by Kitt Peak-Spacewatch (691) on February 18, and later, two observations of 2010 EM34 by G96 on April 10 and April 12, extending the observed arc to 52 days. The 52-day arc determined the orbit well enough to find observations of the object from past years. Namely, the automated procedures linked observations from 1999 (1), 2003 (4), 2005 (1), 2006 (4) and 2007 (1).

2010 EM34, as it turned out, corresponds to 2003 US321 and 2006 JK71 but 2010 EM34 remained the principal designation because it was the observations of 2010 EM34 which were used to link all the past positions together.

Both 2003 US321 and 2006 JK71 were observed on two nights only. 2003 US321 was discovered by 691 on October 16, 2003 and observed again by LPL/Spacewatch II (291) on October 23, 2003. Two one-night observations of the object from September 16 and 28 were also reported but the automated routines at MPC were not able to link the observations to 2003 US321, because they were spaced too far apart (and the two-night orbit of 2003 US321 wasn’t accurate enough). 2006 JK71 was discovered at Mauna Kea (568) on May 1, 2006 and observed again by G96 on May 2, 2006.

Once the link was established, the orbit of 2010 EM34 could be calculated with sufficient precision to link one-night observations from 1999, 2005 and 2007. Consequently, the orbit was determined to be accurate enough so that minor planet could be numbered. 2010 EM34 received a permanent designation 239792 in the Minor Planet Circular 69935 and can now be named.

Sunrise Solstice at Stonehenge. The above image was taken during the week of the 2008 summer solstice at Stonehenge in United Kingdom, and captures a picturesque sunrise involving fog, trees, clouds, stones placed about 4,500 years ago, and a 5 billion year old large glowing orb. Even given the precession of the Earth's rotational axis over the millennia, the Sun continues to rise over Stonehenge in an astronomically significant way - Credit: APOD/Max Alexander, STFC, SPL

Certainly there is no good scientific reason for doing so. In the Northern Hemisphere the period of maximum daylight falls roughly between May 7 and August 7–in other words, the six weeks before and after the solstice. The period of maximum temperature, on the other hand, is June 4 through September 3. (The period of max temperature in the mid-latitudes always lags about 25 to 30 days behind the period of max daylight, due to the fact that the earth heats up and cools off relatively slowly.)

In 2005, thousands of people gathered at sunrise to see the sun rise through the 4,000 year old solar monument - Credit: APOD/ Pete Strasser (Tucson, Arizona, USA)

Here is what the Bad Astronomer has to say about the beginning of season.

Sources: Wikipedia, The Straight Dope, Bad Astronomy / Bad Seasons

Whimsical Vermeer composite that ran on APOD's fifth anniversary now digitally re-pixelated using many of the over 5,000 APOD images that have appeared over APOD's tenure

As during each of the 15 years of selecting images, writing text, and editing the APOD web pages, the occasionally industrious Robert Nemiroff (left) and frequently persistent Jerry Bonnell (right) are pictured above plotting to highlight yet another unsuspecting image of our cosmos. Although the above image may appear similar to the whimsical Vermeer composite that ran on APOD’s fifth anniversary, a perceptive eye might catch that this year it has been digitally re-pixelated using many of the over 5,000 APOD images that have appeared over APOD’s tenure.

It was a great honor to have a link to my blog post appear in the APOD website on October 15, 2009; you may remember:

The brilliant fireball meteor captured in this snapshot was a startling visitor to Tuesday (October 13, 2009) evening's twilight skies over the city of Groningen - Credit: Robert Mikaelyan