Comet science: Rosetta and beyond
Lead Research Organisation:
The Open University
Department Name: Faculty of Sci, Tech, Eng & Maths (STEM)
Abstract
Comets have fascinated, and terrified, people throughout recorded history. The unpredictable appearances of bright comets, even in times when the motions of the "wandering stars" (planets) were well understood, meant that they were treated with suspicion. Today, our knowledge of comets has come a long way, but there are still many puzzles left to solve. As I write this, telescopes and spacecraft scattered all over the solar system are tracking comet ISON as it plunges toward the Sun, but we still cannot predict whether it will light up the sky as a "Great comet" or fizzle out before it arrives.
Nowadays we are interested in comets not as harbingers of doom, but because we can use them to learn about the disc of rock and ice that formed the planets. Comets and asteroids are the leftover "building blocks" from the early days of the solar system; the survivors that didn't get incorporated into one of the planets, crash into the Sun, or get thrown out of the system altogether.
The next few years will be an exciting time in cometary science, as the ESA mission "Rosetta" will be exploring comet 67P/Churyumov-Gerasimenko in great detail. This audacious mission will, for the first time ever, rendezvous with a comet and follow it on its orbit around the Sun. Its array of scientific instruments will watch as the activity of the comet evolves. This mission will not only get closer to a comet than any previous spacecraft (down to only a few km from the surface, flying deep within jets of gas and dust), and be the first to spend an extended period of time watching changes on the comet; it will also land a probe on the surface, to find out exactly what the comet is made of.
I will work on the data that will be returned by Rosetta, especially through the camera system OSIRIS, and also by parallel ground-based observations of the comet. Such ground-based context observations are of critical importance: While the spacecraft will return very detailed information about the nucleus and inner coma of one particular comet, we need to be able to see how these details correspond to the large-scale activity that can be observed with telescopes in order to relate this to comets in general. I am coordinating a campaign of observations from telescopes worldwide. This will include a significant contribution from amateur astronomers, and from UK schools via the Faulkes Telescope project, when the comet is bright enough. Together, these data will reveal how cometary activity works.
In addition to 67P, I will also observe other comets for comparison. These will include those of the same class, the short-period "Jupiter family" comets, and also other types such as main belt and long-period comets, including comet ISON. The interaction between the Sun and comets like ISON, which get very close to the solar surface, not only tells us about how highly active comets behave under extreme heating conditions, but can also reveal new information about the Sun itself and the environment around it. Main belt comets are at the other end of the cometary activity scale: They are a recently discovered missing link between icy comets and rocky asteroids, with asteroid-like orbits but weak comet-like activity. They are also a potential source of Earth's water: It is much easier to have delivered water from the outer asteroid belt to the early Earth than it is to account for all of it from the impact of "normal" comets.
My work will look at the differences in the activity of the three classes of comet (high-activity near-Sun comets, medium-activity Jupiter family comets, and low-activity main belt comets), and the question of whether the variation is due to the different source regions they come from, or due to the environment in which they are active now. This "nature vs. nurture" question for comets will provide clues about the properties of different areas of the planet-forming disc, and the evolution of icy bodies over the age of the solar system.
Nowadays we are interested in comets not as harbingers of doom, but because we can use them to learn about the disc of rock and ice that formed the planets. Comets and asteroids are the leftover "building blocks" from the early days of the solar system; the survivors that didn't get incorporated into one of the planets, crash into the Sun, or get thrown out of the system altogether.
The next few years will be an exciting time in cometary science, as the ESA mission "Rosetta" will be exploring comet 67P/Churyumov-Gerasimenko in great detail. This audacious mission will, for the first time ever, rendezvous with a comet and follow it on its orbit around the Sun. Its array of scientific instruments will watch as the activity of the comet evolves. This mission will not only get closer to a comet than any previous spacecraft (down to only a few km from the surface, flying deep within jets of gas and dust), and be the first to spend an extended period of time watching changes on the comet; it will also land a probe on the surface, to find out exactly what the comet is made of.
I will work on the data that will be returned by Rosetta, especially through the camera system OSIRIS, and also by parallel ground-based observations of the comet. Such ground-based context observations are of critical importance: While the spacecraft will return very detailed information about the nucleus and inner coma of one particular comet, we need to be able to see how these details correspond to the large-scale activity that can be observed with telescopes in order to relate this to comets in general. I am coordinating a campaign of observations from telescopes worldwide. This will include a significant contribution from amateur astronomers, and from UK schools via the Faulkes Telescope project, when the comet is bright enough. Together, these data will reveal how cometary activity works.
In addition to 67P, I will also observe other comets for comparison. These will include those of the same class, the short-period "Jupiter family" comets, and also other types such as main belt and long-period comets, including comet ISON. The interaction between the Sun and comets like ISON, which get very close to the solar surface, not only tells us about how highly active comets behave under extreme heating conditions, but can also reveal new information about the Sun itself and the environment around it. Main belt comets are at the other end of the cometary activity scale: They are a recently discovered missing link between icy comets and rocky asteroids, with asteroid-like orbits but weak comet-like activity. They are also a potential source of Earth's water: It is much easier to have delivered water from the outer asteroid belt to the early Earth than it is to account for all of it from the impact of "normal" comets.
My work will look at the differences in the activity of the three classes of comet (high-activity near-Sun comets, medium-activity Jupiter family comets, and low-activity main belt comets), and the question of whether the variation is due to the different source regions they come from, or due to the environment in which they are active now. This "nature vs. nurture" question for comets will provide clues about the properties of different areas of the planet-forming disc, and the evolution of icy bodies over the age of the solar system.
Publications
A'Hearn M. F.
(2015)
Imaging the Gas from 67P/Churyumov-Gerasimenko
in 46th Annual Lunar and Planetary Science Conference
Fulle M.
(2015)
Dust Measurements in the Coma of Comet 67P/Churyumov-Gerasimenko Inbound to the Sun Between 3.7 and 3.4 AU
in 46th Annual Lunar and Planetary Science Conference
Dominik Martin
(2015)
GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry
in AAS/Division for Extreme Solar Systems Abstracts
{Dominik} M
(2015)
GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry
in AAS/Division for Extreme Solar Systems Abstracts
{Knight} M
(2015)
322P/SOHO 1: Sunskirting Comet or Asteroid?
in AAS/Division for Planetary Sciences Meeting Abstracts
{Fernandez} Y
(2015)
The Distribution of Geometric Albedos of Jupiter-Family Comets From SEPPCoN and Visible-Wavelength Photometry
in AAS/Division for Planetary Sciences Meeting Abstracts
{Davidsson} B
(2015)
The primordial nucleus of Comet 67P/Churyumov-Gerasimenko
in AAS/Division for Planetary Sciences Meeting Abstracts
{Hines} D
(2015)
Hubble Space Telescope Imaging Polarimetry of Comet 67P/Churyumov-Gerasimenko Obtained During the Rosetta Mission
in AAS/Division for Planetary Sciences Meeting Abstracts
{Dias-Oliveira} A
(2015)
Pluto's atmosphere from stellar occultations in 2012 and 2013
in AAS/Division for Planetary Sciences Meeting Abstracts
{Marchant} J
(2015)
Comet 67P observations with LOTUS: a new near-UV spectrograph for the Liverpool Telescope
in AAS/Division for Planetary Sciences Meeting Abstracts
{B{\'e}rard} D
(2015)
Chariklo's size, shape and orientation from stellar occultations
in AAS/Division for Planetary Sciences Meeting Abstracts
Dias-Oliveira Alex
(2015)
Pluto's atmosphere from stellar occultations in 2012 and 2013
in AAS/Division for Planetary Sciences Meeting Abstracts #47
Davidsson Bjorn
(2015)
The primordial nucleus of Comet 67P/Churyumov-Gerasimenko
in AAS/Division for Planetary Sciences Meeting Abstracts #47
Hines Dean C.
(2015)
Hubble Space Telescope Imaging Polarimetry of Comet 67P/Churyumov-Gerasimenko Obtained During the Rosetta Mission
in AAS/Division for Planetary Sciences Meeting Abstracts #47
Knight Matthew M.
(2015)
322P/SOHO 1: Sunskirting Comet or Asteroid?
in AAS/Division for Planetary Sciences Meeting Abstracts #47
Fernandez Yanga R.
(2015)
The Distribution of Geometric Albedos of Jupiter-Family Comets From SEPPCoN and Visible-Wavelength Photometry
in AAS/Division for Planetary Sciences Meeting Abstracts #47
Marchant Jon
(2015)
Comet 67P observations with LOTUS: a new near-UV spectrograph for the Liverpool Telescope
in AAS/Division for Planetary Sciences Meeting Abstracts #47
Snodgrass C
(2018)
The Castalia mission to Main Belt Comet 133P/Elst-Pizarro
in Advances in Space Research
Bowles N
(2018)
CASTAway: An asteroid main belt tour and survey
in Advances in Space Research
Herique A
(2018)
Direct observations of asteroid interior and regolith structure: Science measurement requirements
in Advances in Space Research
Jones G
(2018)
The proposed Caroline ESA M3 mission to a Main Belt Comet
in Advances in Space Research
{Fernandez} Y
(2016)
The Distribution of Geometric Albedos of Jupiter-Family Comets From SEPPCoN and Visible-Wavelength Photometry
in American Astronomical Society Meeting Abstracts
{Lister} T
(2015)
LCOGT Network observations of spacecraft target comets
in American Astronomical Society Meeting Abstracts
Lister Tim
(2015)
LCOGT Network observations of spacecraft target comets
in American Astronomical Society Meeting Abstracts #225
Fernandez Yanga R.
(2016)
The Distribution of Geometric Albedos of Jupiter-Family Comets From SEPPCoN and Visible-Wavelength Photometry
in American Astronomical Society Meeting Abstracts #227
Snodgrass C
(2016)
Distant activity of 67P/Churyumov-Gerasimenko in 2014: Ground-based results during the Rosetta pre-landing phase
in Astronomy & Astrophysics
Hundertmark M
(2018)
RoboTAP: Target priorities for robotic microlensing observations
in Astronomy & Astrophysics
Figuera Jaimes R
(2016)
Many new variable stars discovered in the core of the globular cluster NGC 6715 (M 54) with EMCCD observations
in Astronomy & Astrophysics
Kwon Y
(2021)
VLT spectropolarimetry of comet 67P: dust environment around the end of its intense southern summer
in Astronomy & Astrophysics
Zaprudin B
(2017)
Solar-insolation-induced changes in the coma morphology of comet 67P/Churyumov-Gerasimenko Optical monitoring with the Nordic Optical Telescope
in Astronomy & Astrophysics
Snodgrass C
(2017)
X-shooter search for outgassing from main belt comet P/2012 T1 (Pan-STARRS)
in Astronomy & Astrophysics
Zaprudin B
(2015)
Optical observations of comet 67P/Churyumov-Gerasimenko with the Nordic Optical Telescope Comet activity before the solar conjunction
in Astronomy & Astrophysics
Kains N
(2016)
Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry (Corrigendum)
in Astronomy & Astrophysics
Skottfelt J
(2015)
Searching for variable stars in the cores of five metal-rich globular clusters using EMCCD observations
in Astronomy & Astrophysics
Tubiana C
(2014)
67P/Churyumov-Gerasimenko: Activity between March and June 2014 as observed from Rosetta/OSIRIS
in Astronomy & Astrophysics
Kains N
(2015)
A census of variability in globular cluster M 68 (NGC 4590)
in Astronomy & Astrophysics
Vaduvescu O
(2018)
280 one-opposition near-Earth asteroids recovered by the EURONEAR with the Isaac Newton Telescope
in Astronomy & Astrophysics
Tubiana C
(2015)
2P/Encke, the Taurid complex NEOs and the Maribo and Sutter's Mill meteorites
in Astronomy & Astrophysics
Giannini E
(2016)
MiNDSTEp differential photometry of the gravitationally lensed quasars WFI 2033-4723 and HE 0047-1756: microlensing and a new time delay
in Astronomy & Astrophysics
Davidsson B
(2016)
The primordial nucleus of comet 67P/Churyumov-Gerasimenko
in Astronomy & Astrophysics
Evans D
(2018)
High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP) II. Lucky Imaging results from 2015 and 2016
in Astronomy & Astrophysics
Opitom C
(2019)
2I/Borisov: A C 2 -depleted interstellar comet
in Astronomy & Astrophysics
Moreno F
(2016)
The dust environment of comet 67P/Churyumov-Gerasimenko from Rosetta OSIRIS and VLT observations in the 4.5 to 2.9 AU heliocentric distance range inbound
in Astronomy & Astrophysics
Evans D
(2016)
High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP) I. Lucky imaging observations of 101 systems in the southern hemisphere???
in Astronomy & Astrophysics
Figuera Jaimes R
(2016)
Exploring the crowded central region of ten Galactic globular clusters using EMCCDs Variable star searches and new discoveries???
in Astronomy & Astrophysics
{A'Hearn} M
(2015)
Rotational Variation of Outgassing Morphology in 67P/Churyumov-Gerasimenko
in IAU General Assembly
A'Hearn Michael F.
(2015)
Rotational Variation of Outgassing Morphology in 67P/Churyumov-Gerasimenko
in IAU General Assembly
{Jones} G
(2015)
Castalia \mdash A Mission to a Main Belt Comet
in LPI Contributions
{A'Hearn} M
(2015)
Imaging the Gas from 67P/Churyumov-Gerasimenko
in Lunar and Planetary Science Conference
{Fulle} M
(2015)
Dust Measurements in the Coma of Comet 67P/Churyumov-Gerasimenko Inbound to the Sun Between 3.7 and 3.4 AU
in Lunar and Planetary Science Conference