Author: John Timmer

Artist's conception of a hot Neptune orbiting close to its host star. Kepler-223 has four such planets, all with orbital periods of less than 20 days. By contrast, Mercury's orbit takes 88 days. (credit: NASA/JPL-Caltech)

How did our solar system reach its current configuration? One of the leading candidates to explain things like the sparseness of the Asteroid Belt and the small size of Mars is the grand tack, in which Jupiter originally migrated inward toward the Sun until its interactions with Saturn pulled them both back outward.

The idea that giant planets may go for a wander around their star's orbital neighborhood has picked up some support from many of the exosolar systems we've discovered. We've spotted tightly packed systems of large planets when there probably wasn't enough material in the region to form all of them, suggesting that they formed somewhere else and then migrated into place.

But this idea raises some questions. What stops the planets from their wanderings, keeps them from smashing into each other, and prevents them from falling into their host star? A phenomenon known as orbital resonance may be the answer, and researchers argue that it explains the presence of four exoplanets all with orbits of less than 20 days.

Over the course of the spring, I had the chance to talk about science journalism at a number of universities. (Thanks to the folks at Washington University in St. Louis and the University of Illinois in Chicago for inviting me.) It took about 45 minutes for me to discuss the issues involved and provide a number of examples of things gone badly wrong.

On Sunday, John Oliver managed to cover the same ground and more, and he did it with a lot more flair and humor—all in under 20 minutes. If you have the time, it's well worth a watch.

On Monday, all these science journalism problems were driven home yet again. The University of Gothenburg issued a press release suggesting that hunger influences our decision-making processes. This finding shouldn't be a huge surprise; anything that distracts us seems to influence our ability to make decisions. But the release itself is a perfect example of many of the problems Oliver pointed out.

(credit: LHCb)

After more than a month of checking out the equipment, the Large Hadron Collider is set to return to the frontiers of particle physics. This will be the second run at higher energies after a few years at lower energy and a couple years of upgrades. The plan for this year is to increase the frequency of high-energy collisions in order to get a better view of the Higgs boson and pursue the search for new particles.

After suffering a catastrophic failure early in its history, the LHC was run for several years at energies that created collisions at seven or eight Tera-electronVolts. This was followed by an extended shutdown that upgraded hardware and fixed the defects that caused the earlier failure. Last year's physics run was the fist at 13TeV, and the collider's operators were relatively cautious as they learned how to control the machine at these higher energies.

The new energies provide two major advantages. Since new particles are created by converting energy to matter, the higher the energy, the heavier the particles you can produce. And some analyses have been finding hints that there might be a new particle in the neighborhood of 750 Giga-electronVolts—nearly 800 times the mass of the protons that were smashed to create it.

(credit: US EIA)

US carbon emissions were down slightly in 2015, continuing a period in which economic growth has been accompanied by relatively flat emissions. Compared to 2005, however, the current numbers represent a 12 percent drop. The Energy Information Agency (EIA) indicates this has largely been caused by the transition from coal to natural gas.

US carbon emissions saw a significant drop during the 2008-2009 economic crisis, driven largely by falling economic activity. As the economy began to rebound in 2010, so did carbon emissions. But succeeding years have seen a series of relatively minor ups and downs—the current numbers represent a drop of about two percent compared to 2014. Notably, the emissions are also below those at the height of the economic crisis in 2009.

That's rather significant, as economic growth has been consistently in the neighborhood of two percent since 2010. This provides a strong indication that, for the moment at least, the US has decoupled economic growth from carbon emissions. Overall, the economy is up about 15 percent since 2005 when inflation is taken into account.

(credit: Wikimedia Commons)

Clinical depression is a devastating disease that is made worse by the lack of effective treatment. Several drugs can treat the disease, but they take months to become effective, often causes side effects, and only work in a subset of the patient population. Treatment often begins with an extended period of trial and error, sometimes taking over a year.

Ketamine provides a shortcut. The drug can often lift symptoms of depression in under 24 hours, and the effects persist for roughly a week after a single administration. So why isn't everybody using it?

Well, ketamine comes with some pretty dramatic side effects. At high concentrations, it creates a combination of sedation and pain relief, while blocking memory use, making it an effective anesthetic. At lower concentrations, it produces a dissociative state, which has led to the drug being used recreationally. In either case, coming down from these states tends to produce disorientation and sometimes more severe problems. So, ketamine is not quite ready for widespread use.

The complex pattern left behind by liquid water flowing through sand under Martian atmospheric pressures. (credit: M. Massé)

We now know that there is liquid water on the surface of Mars. Streaks of dark material flow down crater walls, appearing and disappearing with the seasons. Imaging from orbit has confirmed that these features contain hydrated salts, leading researchers to conclude that the water took the form of a salty brine, which would prevent it from immediately evaporating into Mars' cold, thin atmosphere.

But a new paper released today argues that we might want to rethink the role of brine. The international team behind it tested what would happen if pure water were flowing through sand under Mars-like conditions. Some of the water boiled off quickly, but it managed to spread a bit further than expected and produced features similar to some that have been imaged from orbit.

There are a number of challenges with figuring out what's happening on Mars. The first is that we've got no hardware anywhere near where the watery features form; all our direct exploration has to take place from orbit. Another challenge is that we don't know the nature of the water. At Martian pressures, pure water could boil at temperatures reached in the daytime and freeze at night, while salts could keep it liquid at the prevalent temperatures.

The dread cabbage looper. (credit: Peggy Greb/USDA)

Bacillus thuringiensis (Bt) crops have been one of the most successful applications of genetic engineering in agriculture. The crops carry a gene that encodes a bacterial protein that kills insects that ingest it. While it's possible to spray crops with the Bt toxin instead, farms that rely on Bt GMO crops are more profitable, have higher productivity, and use less pesticides.

Unfortunately, evolution isn't sitting still, and Bt-resistant insects are beginning to become a problem. While scientists are developing new crops with other Bt genes and farmers can adopt agricultural practices that limit the risk of resistance, some researchers decided to short-circuit the whole process. In a new paper, they figured out how to evolve a completely new Bt toxin in a virus that infects bacteria and showed that it was effective in killing insects.

The basics of Bt

The researchers' work highlights the importance of basic, fundamental research—while a handful of the research team worked at Monsanto, two-thirds came from various academic institutions. And the work relies on some basic information that's not essential to using Bt in GMOs.

Enlarge / The arrow points to the very faint moon near Makemake. (credit: NASA, ESA, and A. Parker)

Today, NASA announced that images it has been sitting on for a year show a moon orbiting a dwarf planet in the Kuiper belt. The moon, formally known as S/2015 (136472) and going informally as MK 2, is in orbit around Makemake, a dwarf planet two-thirds the size of Pluto that spends most of its time more than 40 Astronomical Units away from the Sun (1 AU is the typical Earth-Sun distance).

MK 2 is more than 1,300 times fainter than the planet it orbits, largely because it has a very dark surface compared to Makemake's icy white color. It also appears to orbit within the plane of the Solar System, which means it's indistinguishable from Makemake for much of its orbit—Hubble managed to catch it when it was more than 20,000km from the dwarf planet. Estimates are that MK 2 is about 160km across compared to Makemake's 1,400km.

Early observations show that the orbit takes at least 12 days, and the shape of the orbit is roughly circular. This data suggests that MK 2 formed from debris liberated from Makemake by an impact; passing objects that are captured by planets typically have eccentric orbits. Detailed observations of MK 2's orbit will allow us to determine the density of Makemake, which will then tell us something about its composition, so NASA will continue observing the new body.