So, as you might have heard from the numerous media reports which are not exaggerating one bit to what I can tell, planet nine has officially been found in the outer solar system- indirectly at least. you can find more about it here: https://en.wikipedia.org/wiki/Planet_Nine I will spare all the details about it and get straight to the meat: It has not been directly detected. Many surveys are underway to detect it, including a number of large dedicated telescopes. I will toss my hat into this too, using my already extensive knowledge of the Sloan Digital Sky Survey, as well as using data from 2MASS, WISE, DSS, and other surveys. I will post updates in chunks by RA and DEC to this blog. Expect many updates to follow. ~Sam Deen (Planetaryscience)

Ceres: What to expect soon, and the mysterious bright spot

2015 will be relatively full, as years go, of space exploration. Not only will we finally get our first pictures of Pluto later this year, but the Dawn probe will become the first probe to image a dwarf planet in detail, and observe the only object in the Asteroid Belt with enough mass to pull itself into a sphere. On January 13th, the Dawn probe imaged Ceres for the first time with a higher resolution than any telescope before. Although it didn't reveal much about Ceres's surface that we don't already know, it shows the beginning of the approach to Ceres in the next month. In only one month and 11 days we will have unprecedented images of Ceres, revealing all the details of this elusive dwarf planet.

Speaking of details, many images of Ceres have revealed what appears to be a bright spot near Ceres's equator. It's certainly not a temporary feature, as images of Ceres from both the Hubble Telescope and Dawn, spaced over 10 years apart, show the same feature:

Ceres as taken by the Hubble Telescope in 2003-2004

So, let's do somethinking.

In 2003-2004 the object, whatever it was, was much more visible and bright than it is now. Plus the object appears to be inside a crater from the Dawn image.

Firstly, it could be ice. Craters have been known to be filled with ice previously. Ceres is likely no exception. However this ice deposit is near the equator, which would mean that it would have boiled away by now. Any source of ice would have to be replenished constantly, perhaps by the recently-discovered theoretical subsurface ocean.

On the topic of ice brings me to the second possibility. Earlier Hubble had observed ice around Ceres, in the atmosphere around it. This may be a geyser fueling the cloud of ice around Ceres. However it doesn't appear to have much of a height to it.

Either way, we'll find out what it is eventually when we reach Ceres. Perhaps it's just a gigantic sticker.

the North Caribou Lake impact crater

As you may know, Canada is absolutely full of impact craters. In fact, of the 10 largest craters on Earth, Canada contains 5 of them - but it just might contain 6. In Northwestern Ontario lies North Caribou Lake- another 20 km wide reminder that Canada once had glaciers. Yet from a satellite view it appears to occupy a vast egg-shaped formation made obvious by the Eyapamikama Lake to the north and an unnamed river to the south. Continuing to look around the area will reveal more features appearing to make a circular shape around 52.59706 N 90.824734 W. In total, the crater appears to measure at least 50 kilometers wide, making it the 15th largest possible crater on Earth (not including uncomfirmed craters)
Unfortunately the crater is in the middle of nowhere, the nearest town to it is Pickle Lake, with a population of only 425.

I could of course try to report it to the Earth Impact Database but they require evidence of an impact crater versus a geologic dome or volcanic crater - shatter cones, shocked quartz, impact breccia, etc etc. All of this would require a visit to the crater, yet I have neither the money or the time to do this any time soon. So I ask, by the off-chance anyone lives near the crater, consider taking a trip there and look for any of the above mentioned features.

In the mean time, I'll be saving up to go there myself.

Either way, happy New Year!

happy MJD 2457000.0!

Most of us know today as a rather unimportant day, as days go, with the rather unimportant number of December 8th. However if you're familiar with a timekeeping method used in many astronomy fields, then you'll know that from 12:00 today to 12:00 tomorrow is the julian date 2,457,000.

First, a brief history. The Julian date is a count of the days that have passed since January 1st, 4713 BC. It is used in timekeeping for astronomy to count individual days since that date, and in the case that I most often see, to provide epochs for minor planets' orbits. Today, exactly 2,457,000 days have passed since the count was started. 2456000 was March 14th, 2012 and 2458000 will be on September 4th, 2017.

So, happy JD 2457000!

67P/Churyumov-Gerasimenko's double lobed shape

By far the most interesting and defining quality of comet 67P, when the Rosetta Probe visited it earlier this year, was its double-lobed shape. While not being completely new, this was the first example of such a process happening with a comet.

Contact binaries are assumed to have been two asteroids (or comets) that joined together through a collision slow enough that they wouldn't fly past each other, or destroy each other. A defining quality for these is the notable double-lobe nature of them when a telescope points itself at them. Naturally, based on the images, that's what I would have thought if I didn't know better. However I have a couple of reasons to believe otherwise.

First, long exposure images of the comet have found that both lobes of the comet are erupting. And, based on a JPL small-body database search, asteroids outnumber comets just a bit over 200:1. The chances of two comets merging together is less than 0.1%. To further this, every picture taken shows most of the outgassing coming from the center of the comet, along with the shape of the comet indicating that the area was dug away rather than gravitationally connected- a contact binary owuld have a distinct divider between each asteroid, with gravitational attraction flattening only the closest parts to one another, giving it more of a bowling pin look than an apple-core look.

Second, the density of the comet is 0.4 g/cm³, which is typical of a comet, but based on such a size and a density, a contact binary alone would not be sufficient to mold the two lobes of the comet together to such a high degree. Plus, you would expect the density to be higher had two asteroids collided with each other, pushing each other together and giving a density of at least a few more decimals than the found density.

Lastly, notice that, contrary to the rest of the comet, the 'bridge' is relatively smooth, without any craters. This shows that the surface is young in comparison, and that any craters that form are quickly wiped away as the dust that they are imprinted upon flies off the comet.

Based on the given evidence, I can conclude that 67P is a single comet, but through an unknown force, the center of it is being melted away quicker than the rest of the comet, and that we are perhaps observing live exactly how comets fragment. It may be quite a while before this one fragments, but I think the mechanism behind this quicker core sublimation would be a good target for more in-depth study, and that it will help us better understand exactly how comets work.

Updates

again, sorry for the delay. I know the blog hasn't been very active, but I've never seen a blog that updates much more than once a week. Anyways, here's what happened since my last post.

I've finished my list of comets by type on wikipedia - https://en.wikipedia.org/wiki/List_of_comets_by_type

I also started another project to find transneptunian objects from SDSS data - so far I've found images of 10, two of which I found from before they were discovered, 2004 XR190 and 2011 GM27.

I recently found what should be precovery observations of the asteroid 2014 UM33, however it only has an observation arc of 2 days, and is currently magnitude ~20. If there's anyone who can observe it in the next few days, for me to get an observation from 2009-01-17, that would be quite helpful. The asteroid probably needs a 2-meter telescope or larger, or at least a telescope that can see to mag=20.

more updates in the next few months!

Have we already made first contact?

It's something science fiction readers and writers love to talk about all the time. Making first contact with another civilization would of course revolutionize everything about the way we live. Of course the typical science fiction book will lead you to believe that first contact is in the form of direct contact with alien races, as in meeting them in person, but it's much more likely that our first form of contact will be through signals sent to one another, and chances are that's going to take a long time, which brings me to the topic this post is on.

While we've only sent out signals to distant worlds for the last decade or two. Just traveling at the speed of light, not taking into account the decrease in signal strength over distance, we've only reached a few hundred stars, most of which are red or brown dwarfs. However, we've unintentionally been sending out signals for much longer, going back into the early 20th century, however most early signals were only intended for short-distance communication and likely wouldn't get beyond the orbit of the Moon, much less interstellar space. However more intense radio signals have been used over time, to a point where our planet is essentially a beacon of radio waves in space. Of course any civilization within 50 light years, with sufficient signal sensitivity, would have already noticed us and possibly recognized us as a civilization. But how long would it be before we made contact?

Well assume we send out a signal in 2000 AD, and it reaches an alien civilization 50 light years away. By the time it reaches them, it's 2050. It would be 2100 before we receive any signal whatsoever from them, and much longer for them to reach us. Even if they traveled at 1/10th at the speed of light, or ~1,086 miles per second it would take them 500 years. In other words, if a civilization recognized we exist recently, we won't know for quite some time, and if decide not to send any signals before arriving, it could take until at least 2500 AD before we know.

Then its also possible we've already found alien signals long ago. On August 15, 1977, Jerry Ehman, working for SETI using the Big Ear radio telescope, detected a radio signal coming from the constellation Sagittarius. The location is fairly uncertain, and is limited to between two narrow bands in the area, neither of which contains any remarkable stars. Chances are that whatever the signal came from is very distant, leaving one to wonder how strong the signal sender would have to be. According to one source, it would have to be approximately 2,200,000 watts of power. For comparison the strongest signal transmitter on Earth is only 2,500 watts, roughly 1/1000th of the required amount. Whether or not it came from an intelligent civilization is likely something we won't know for quite a long time.