Planetary News: The Battle For Zarmina's World Rages On

Gliese 581g (Zarmina's World); artist's concept

Gliese 581g, better known to this blogger and his readers as Zarmina's World, remains the centre of controversy. Earlier this month I posted about how the Goldilocks planet was gaining support. Astronomers Guillen Anglada-Escude and Rebekah Dawson agreed that the extant data supported the conclusions made by Dr. Steven S. Vogt and his colleague, Dr. R. Paul Butler. Likewise, the University of Puerto Rico, an accredited academic institution, has given support by default, by placing the planet at the top of the list of potentially habitable worlds (thus meaning it outranks every non-controversial exoplanet known to man). So it's not as if Drs. Vogt and Butler are simply digging their heels in the sand like stubborn mules. There are other authorities which lend support to the claim that the data we have concerning the Gliese 581 star system supports at least five planets, one of them being Zarmina's World. That should raise more eyebrows than it is.

Opponents of the claim have been very slow with their own counter-interpretations. Michael Mayor, famous for discovering the other planets of the system (as co-discoverer with Stephane Udry), contends that the data argues against the existence of Zarmina's World. Together with his team, Mayor re-analyzed the data, and stated plainly that the planet does not exist, although he waited a year to publish his paper. Mayor's claims have won over the majority of the scientific community, including one of Vogt's former students, Dr. Artie P. Hatzes, who said he was pained to see his former mentor clinging to conclusions that were, "obviously wrong." Another denier was Dr. Thierry Foreveille, who claims that his analysis of the data supports Mayor's: a system of four planets with elliptical orbits. However, Foreveille's data has not yet been published in a peer-reviewed journal. This prevented Dr. Vogt from publishing a response in most current and leading scientific journals.

Dr. Steven S. Vogt. Photo (c) LaurieHatch.com

Despite the negative feedback and the slow responses of the deniers, Dr. Vogt and Dr. Butler have been stalwart. Vogt rejects the claims of Foreveille and says that such a system would be unstable. Circular orbits are a better match, and when the system is observed with this in mind, the data points clearly to the existence of a fifth planet. Even though most scientific journals won't accept Vogt's counter until Foreveille publishes his article in a peer-reviewed journal, there is one that will take Vogt's reply: the Astronomische Nachrichten, which just happens to be one of the oldest scientific journals in the world. They have accepted his article and published it. Foreveille was quick to respond that elliptical orbits for the Gliese system are in fact stable, and that Vogt's paper is wrong. He says the probability that Vogt's planet is a "false alarm" (the term used for false planetary detections) has risen to 4%, which is apparently a bad sign. Dr. Greg Laughlin of the University of California, Santa Cruz, raises the estimate to 12%. But let's think about that math for a minute. Even if Laughlin is correct, that still means Vogt has an 88% chance of being right. While that may not be enough to speak with certainty as to the planet's existence it is also a far cry from dismissal. To his credit, Laughlin is being a fair scientist. For Mayor and Foreveille, the non-existence of Zarmina's World is a foregone conclusion. Laughlin, however, admits that Vogt has "a decent shot" of being correct, and further adds that, "[I]t is likely that if the peak holds up as more data comes in, the planetary explanation is likely to be correct." For that I give props to Dr. Laughlin. He is telling it like it is.  Vogt is confident is his data, and I am confident in him. But, like Dr. Laughlin, we must be honest. It's not an indisputable fact just yet. The odds are definitely in favour of Zarmina's World existing, but we don't know for sure just yet. Only time will tell. But I would not be surprised in the least if in the next year or two we hear that Zarmina's World has been confirmed.

(all quotations and details taken from a New York Times article

 http://www.nytimes.com/2012/08/21/science/space/just-right-or-nonexistent-dispute-over-goldilocks-planet-gliese-581g.html ; All other material is the opinion of the author of this blog)

Planetary News: Zarmina's World gains support

Zarmina's World. Discovered nearly two years ago by Steven S. Vogt and his team, this planet (officially designated as Gliese 581g, Gl 581g or GJ 581g) has been the topic of discussion, debate, and controversy ever since. Nestled perfectly within the habitable zone of its parent star, Zarmina's World (Zarmina for short) was the first planet ever discovered by man to fit so perfectly into our hopes for a habitable world. Dubbed "Goldilocks Planets" because of the story where Goldilocks had to have everything "just right" these perfectly habitable worlds were expected to exist, but had never been found. Until Zarmina. Zarmina, more than any other discovered exoplanet to date, deserves the nickname of "Goldilocks Planet" because of how perfectly situated within the habitable zone it is.

However, not everyone was excited by the news. Michael Mayor and his team, who with Stephane Udry had been crucial to the discovery of the first four planets in the system, wasn't so sure that Vogt had really found two new planets. They analyzed the data, reanalyzed it, and did it again. When they were finished, they published a paper with their own conclusions: Vogt's two new worlds did not exist. The controversy was born. Had Vogt discovered two new planets, including the most unimaginably perfect Goldilocks Planet to date? Or were his findings wrong?

As mentioned in my early "Planet Profile: Gliese 581g" post, other astronomers quickly went to work assessing the data. Some supported Mayor and said the facts just didn't fit, Zarmina and Gl 581f did not exist. Others countered that the data is sufficient to support Vogt's claim. It was no small matter within the astronomical community. Either Vogt had found the sweet-spot, or he hadn't.

Vogt and his team weren't going to give up. They took all of the data that Mayor et al. had studied, and went through it again. Very thoroughly. On August 1 of this year they published their results. The outer world, Gl 581f was still up in the air, but Zarmina was confirmed. Vogt told space.com that the data they studied, "point to there being at least one other planet beyond the confirmed 4, a 5th planet, with a[n orbital]  period  in the 26-39-day regime." (source: huffingtonpost.com) Vogt would add that although the data examined does not support planet f, the idea of that planet is not dead yet. Further studies may yet prove its existence. But as for Zarmina, the planet is definitely there.

While the scientific and academic community as a whole has not yet accepted the planet's status as "confirmed" some academic institutions are taking initiative. The University of Puerto Rico at Arecibo's Planetary Habitability Laboratory recently published a list of habitable exoplanets, and Gliese 581g makes the top of the list. UPR may not be the most prestigious school in academia, but it is nevertheless a solid, accredited academic institution. And they have accepted Vogt's new data as sufficient to settle the case. Zarmina exists, and her status as the truest of Goldilocks Planets is secured. The list ranks Gliese 581g at the number one spot, with an SE (Similarity to Earth) rating of 0.92. Her sister planet of Gliese 581d (the original gem of the Gliese 581 system) ranks number 5 with a rating of 0.72. Numbers 2 - 4 are Gliese 667Cc (0.85), Kepler-22b (0.81), and HD 85512b (0.77). In the near future, look for me to do some Planet Profiles on these other top-rankers in habitability. But for now, I think it is safe to say that Zarmina's World exists, and she is fit snugly in her habitable zone. 

What wonders has God placed on this world for future generations to explore? God-willing, we may be able to get our first tastes within our lifetimes, but that would require revolutionary new advances in space travel. The Voyager probes only recently reached the edges of our Solar system, and have a bloody long way to go before they could even reach a next-door-neighbour like Alpha Centauri. On a galactic scale, the 22 light-years between the Solar system and the Gliese 581 system is a mere stone's throw. But with current technology, it is an almost unbridgeable gap, and certainly one we cannot bridge in a single lifetime. But we can dream, can't we?

             

Upcoming Perseid Meteor Shower

There are several meteor showers visible per year. The next on the list is the one known as "the Perseids." Their name comes from the Greek for "the sons of Perseus" because they appear to emanate from the constellation that bears the ancient god-hero's name. The Perseids first appeared (or at least, are first mentioned) in AD 36, and have been a yearly recurrence ever since. They are also known to many Christians (especially Catholics) as the "Tears of St. Lawrence" because they tend to peak on or around his feast day of August 10. And yes, this is the same St. Lawrence who, according to tradition, was grilled alive and when told his suffering could end if he renounced Christ, instead replied, "Turn me over, this side's done." Now that we have the historical curiosities aside, let us get to the real matter of the meteor shower.

The Perseids generally begin in late July (typically the 23rd) but they're not too intense yet. If you sit outside and watch the night sky in late July or early August you'll see some, but not a great amount. This year, their peak is expected to come on the night of August 12 - 13. So on or around that date will be your best bet for viewing, and they will continue to adorn our night sky until August 24th or thereabouts, so if you miss the peak don't fret, you'll still have a chance to see them. But the nights of August 10 - 15 or so will be the best for viewing, with 12 - 13 being the most spectacular.

It is recommended that you rise early (about 3:30 or 4am to beat the sun) and view the shower in the predawn hours, when the earth's rotation scoops more of them up as it rotates toward the sun and thus provides the most awe-inspiring show. But if that is too early for you, there will still be plenty to see in the late evening, when the sun has fully set. For best viewing, you should drive away from city lights, and preferably away from busy roads (as passing car lights will hurt your night vision). State or city parks are a good example of places to go, or open fields. Bring lawn chairs, sleeping bags, blankets, or something else to sit in or recline on (you will not want to lie down completely, best visibility will be if you are looking about half-way at the sky). The more comfortable the better. Dress warmly, since the night air can be chilly, even in summer. Bug spray and water bottles are also recommended. You won't need binoculars, the meteors will catch your eye easily. And if you watch during the peak days, you can see as many as 60-100 meteors per hour or more (record for the Perseids is 173 in one hour, back in 2009). That's all I have for you. Happy hunting and enjoy the show!