New Astrobites Post: Colors of Kuiper Belt Objects Reveal Their Histories

Another month, another post for Astrobites!

For today’s post, I wrote about a paper published by the Colors of the Outer Solar System Origins Survey team. They compiled a collection of 229 Kuiper Belt Objects (KBOs) that all have well-measured colors. By “color,” I mean that the astronomers obtained images of the KBOs in three different wavelength filters, and since the objects might not reflect the same amount of light in each filter, the difference between the three measurements gives an idea of the “color.” Just like how plants appear green because most of the light they reflect is green light.

There’s an additional complication, since the reflected light in question is the Sun’s light. The Sun inherently has its own color, and so colors of KBOs tend to be measured relative to the Sun’s color. Colors close to the Sun’s are referred to as “solar neutral” or “gray,” while redder KBOs are referred to as “red.” (There aren’t really any bluer-than-solar objects, though people sometimes confusingly refer to gray KBOs as blue instead, mostly to mean “not-red.” But the objects aren’t actually blue! Luckily the authors of this paper didn’t use that terminology).

What’s so special about color? It turns out that an object’s color corresponds to its composition, and its composition relates back to where in the early planetary disk the object formed. Furthermore, other properties about the object, such as its orbital inclination (how far the object swings out of the plane of the eight major planets), also tell us about the object’s history. Did it form closer to the Sun and get scattered out? Did it form farther out? Considering both inclination and color together could be a powerful constraint on where KBOs formed and how they got to where they are now!

I won’t spoil the punchline, though. You’ll have to go read the post!

New Astrobites Post: A Binary Jupiter Trojan Reveals the Solar System's Early History

Image is an artist’s rendition of Patroclus-Menoetious. Credit: W.M Keck Observatory/Lynette Cook

My latest post for Astrobites is now live!

In this post, I reviewed a paper that studied a peculiar binary asteroid system called (617) Patroclus-Menoetius that orbit around the Sun in a similar path as Jupiter (just 60 degrees behind Jupiter in its orbit). Binary systems contain two similarly-sized objects in orbit around a mutual center of mass (think more along the lines of Pluto and Charon, rather than the Earth and Moon). Binary asteroids are interesting because they’re likely some of the oldest relics in the Solar System. They probably formed when the cloud of “pebbles” that comprised the early planetesimal disk was still condensing and could easily form pairs of objects. Over time, though, encounters with other objects (like other asteroids or big planets) can disrupt binaries, causing them to collide or drift apart. The fact that Patroclus-Menoetius has survived the entirety of the Solar System’s lifetime can put some strong constraints on possible events in the Solar System’s history that would have otherwise disrupted the pair. The authors of the paper ran simulations of the early Solar System to figure out the conditions in which a binary pair like Patroclus-Menoetius could survive.

I won’t spoil the answer here, you’ll just have to go read the post! But what’s especially exciting is that NASA’s Lucy mission, due to launch in 2021, will visit this curious binary system in 2033. So we’ll soon know even more about this system and be able to place even stronger constraints on conditions in the early Solar System!

New Astrobites Post: Using Simulations to Predict the Solar Corona

My latest post for Astrobites is now live!

For the paper I covered, I got to relive a little bit of the amazing experience that was the 2017 total solar eclipse (I wrote another blog post about it here). Total solar eclipses provide us with rare opportunities to study parts of the Sun that are otherwise completely outshone – namely, the corona. The authors of the paper used observations of the Sun’s magnetic fields in the weeks leading up to the eclipse to try to predict what the corona would look like on the day of the eclipse – in other words, they were trying to predict space weather!

They did reasonably well, but they also clearly demonstrated that we don’t have nearly enough instruments taking data of the Sun to be able to accurately predict its weather. But we need to be able to do this, because a powerful solar storm has the potential to knock out our satellites, electrical grids, and other various technology we use to survive! With enough advance warning, like that provided by space weather forecasting, we could mitigate the harmful effects of a solar storm.

New Guest Blog Post: Incentivizing #scicomm for Early Career Scientists

Me, presenting the solar system at an outreach event at the Detroit Zoo.

I recently wrote a blog post for the Union of Concerned Scientists as part of their annual Early Career Scientists (ECS) Month. As an ECS myself, and as a passionate science communicator, I knew exactly what I wanted to write about – providing more incentives for ECS to participate in science communication and outreach.

Nowadays, it’s incredibly hard to “make it” in the academic world – you need to spend upwards of 60 of 70 hours working every week and publish lots of papers. All of that means there’s less time for other enjoyable activities, like outreach. Currently, many positions in the academic track don’t credit outreach work. In fact, that time spent on outreach might ultimately penalize you because you ended up publishing fewer papers in the end! I strongly believe that outreach work should be rewarded and encouraged, at the very least to give back to the people whose tax dollars we’re using to do our work.

New Astrobites Post: The Milky Way Used to Have a Sister Galaxy

My newest Astrobites post is live!

This post was extra fun to write because the authors of the paper I covered work right down the hall from me in the University of Michigan Astronomy department! (No conflicts of interest though, my work has nothing to do with theirs.)

The authors compared a variety of observations of the Andromeda galaxy and its weirdly compact elliptical companion, M32, to results of simulations they had run. They found that M32 was likely much, MUCH bigger about 2 billion years ago, right before Andromeda consumed it. In fact, we now think that M32 used to be the third largest galaxy in our nearby cosmic neighborhood! Talk about a big meal (for Andromeda, that is).