Tag Archives: Neptune

NASA Space Place – Is There A Super-Earth In The Solar System Out Beyond Neptune?

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in August, 2016.

By Dr. Ethan Siegel

2013february2_spaceplaceWhen the advent of large telescopes brought us the discoveries of Uranus and then Neptune, they also brought the great hope of a Solar System even richer in terms of large, massive worlds. While the asteroid belt and the Kuiper belt were each found to possess a large number of substantial icy-and-rocky worlds, none of them approached even Earth in size or mass, much less the true giant worlds. Meanwhile, all-sky infrared surveys, sensitive to red dwarfs, brown dwarfs and Jupiter-mass gas giants, were unable to detect anything new that was closer than Proxima Centauri. At the same time, Kepler taught us that super-Earths, planets between Earth and Neptune in size, were the galaxy’s most common, despite our Solar System having none.

The discovery of Sedna in 2003 turned out to be even more groundbreaking than astronomers realized. Although many Trans-Neptunian Objects (TNOs) were discovered beginning in the 1990s, Sedna had properties all the others didn’t. With an extremely eccentric orbit and an aphelion taking it farther from the Sun than any other world known at the time, it represented our first glimpse of the hypothetical Oort cloud: a spherical distribution of bodies ranging from hundreds to tens of thousands of A.U. from the Sun. Since the discovery of Sedna, five other long-period, very eccentric TNOs were found prior to 2016 as well. While you’d expect their orbital parameters to be randomly distributed if they occurred by chance, their orbital orientations with respect to the Sun are clustered extremely narrowly: with less than a 1-in-10,000 chance of such an effect appearing randomly.

Whenever we see a new phenomenon with a surprisingly non-random appearance, our scientific intuition calls out for a physical explanation. Astronomers Konstantin Batygin and Mike Brown provided a compelling possibility earlier this year: perhaps a massive perturbing body very distant from the Sun provided the gravitational “kick” to hurl these objects towards the Sun. A single addition to the Solar System would explain the orbits of all of these long-period TNOs, a planet about 10 times the mass of Earth approximately 200 A.U. from the Sun, referred to as Planet Nine. More Sedna-like TNOs with similarly aligned orbits are predicted, and since January of 2016, another was found, with its orbit aligning perfectly with these predictions.

Ten meter class telescopes like Keck and Subaru, plus NASA’s NEOWISE mission, are currently searching for this hypothetical, massive world. If it exists, it invites the question of its origin: did it form along with our Solar System, or was it captured from another star’s vicinity much more recently? Regardless, if Batygin and Brown are right and this object is real, our Solar System may contain a super-Earth after all.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

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Caption: A possible super-Earth/mini-Neptune world hundreds of times more distant than Earth is from the Sun. Image credit: R. Hurt / Caltech (IPAC)

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Observing Update: North Sportsman’s Club Session Is ON For Tonight, Saturday Oct. 10th

Greetings fellow astrophiles!

A red-lit view of the NSC building (and several tens of billions of stars towards the galactic center).

It’s looking good enough tonight for the session (very partial cloud cover, which is good enough given past scheduled events), so we’ll be at NSC from 8 to 11. We’ll lose Saturn soon after 8:00 p.m. to our Southwest, leaving Neptune and Uranus as the planetary viewing for the night (and we can, at least, look in the direction of Pluto). The night will be peppered with great objects, from our own backyard to sights beyond our Local Group.

The NSC in google maps. Click to generate directions.

For additional details, check out our original post: Two (Maybe Three) Saturday Sessions Announced For The North Sportsman’s Club – Sept 12th, Oct 3rd, And (Maybe) Oct 10th

CNYO Observing Log: Clark Reservation State Park, 21 August 2015

Greetings fellow astrophiles,

With Perseid Week just behind us, Bob Piekiel and I set up shop for one final Summer 2015 observing session at Clark Reservation. As was mentioned in a Clark Reservation post from last year, it isn’t a great location for heavy-duty amateur astronomers – Syracuse (and its light pollution) lies very close to my hometown of Jamesville (or vice versa, I guess) and even thin cloud cover acts as a dirty mirror to brighten the ground (and sky) around us. For the new observer, however, Clark Reservation is an excellent spot to get one’s feet dewy – it’s close to civilization (and easy to find) and the light pollution wipes out many of the dimmest stars (it probably isn’t far off to say that the sky goes from 2000 to only 400 visible stars thanks to stray city light), making constellation identification significantly easier.

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Early attendees listening to the first welcome lecture.

The session started slowly enough around 8:00 p.m. with a small group of attendees present for our introductory observing lecture/white light warning/usual canned schtick. It wasn’t until after we hit the 40 people mark that I found out that this session was mentioned in the Post-Standard paper as a Weekend’s Best. As we hit the near-80 people mark, we both turned up the lecturing knob to keep people informed and entertained as the observing lines cycled through our two scopes. The crowd was excellent, interactive, and very patient.

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A shot of half the crowd waiting for the ISS.

Every year, I find that some aspect of observing gets a kind of special attention that then becomes part of session dogma (past years being the focus on the hiding of smartphones and flashlights, the very deliberate explanation of how to (and how not to) observe through the scope, and the emphasis on the circumpolar constellations as the best way to get into seasonal constellation identification). The purposes of each of these is, simply, to simplify the session for the attendees (call it a “crash course” in observing). This year, it’s been observation by way of a “hierarchy of observables” (something that Bob and I both have used often). It goes as such:

Early in the evening (including before sunset), non-solar observers have the Moon in all its grandeur (itself possibly the best observable there is for amateur astronomy). While all of the classical planets (Mercury, Venus, Mars, Jupiter, and Saturn) can also be observed, they require a little more time to get to the point of being interesting. Maybe 20 minutes after sunset. By the time that Vega, Arcturus, Deneb, Antares, and Altair are visible (usually coincident with the planets), the most prominent double stars in the sky are visible enough for decent magnification (here, specifically mentioning Albireo in Cygnus and Mizar and Alcor in Ursa Major). Another 20 minutes later, the brightest Messiers are visible – specifically M57, the Ring Nebula in Lyra and M13 in Hercules. 20 minutes later, some of the dimmer Messiers become (just) observable – here, the Andromeda Galaxy (M31 and M32) in Andromeda, and M27, the Dumbbell Nebula in Velpecula. 20 minutes later (so we’re now 80 or so minutes after sunset), the Messier gates flood open and one can begin to make out more objects than can usually be gotten through with a +40 crowd in 2 hours anyway.

Add to this list the ISS, Iridium Flares, random other satellites, a few shooting stars, and some of the detail of the Milky Way inside of Cygnus and down to as much of Sagittarius as the tree line will allow, and you’ve (hopefully) gone a long way to introducing a brand new observer to some of the very best sights available in the nighttime sky (with the above list obviously biased towards the Summer and Fall skies).

To the list above (with only Saturn and Neptune in the planetary observing list), we added at least two meteors (one in the right direction for a Perseid, one not) and a dimmed, by still present, Milky Way band. The lecturing itself didn’t stop for the entire two hours, and we were thankful for the questions that kept us (and others around us) occupied.

With the end of Summer in sight, part of CNYO’s yearly outreach will now include more library lectures and, of course, Bob’s monthly sessions at Baltimore Woods. Stay tuned for event announcements!