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News Archive

6.19.19 The Comet Interceptor mission, on which I am consortium member, was selected as ESA's new 'fast-class' mission! It is scheduled to launch in 2028.

5.17.19 I was awarded a Distinguished Research Scientist Prize for 2019 by the Department of Astronomy!

3.28.19 "Properties of the Bare Nucleus of Comet 96P/Machholz 1" by Eisner, Knight, et al. and "Stellar Occultation by Comet 67P/Churyumov-Gerasimenko Observed with Rosetta’s Alice Far-Ultraviolet Spectrograph." by Keeney et al. are now accepted by AJ and available on arXiv.

1.2.19 Two papers I've been heavily involved in are moving along. "Gas Jet Morphology and the Very Rapidly Increasing Rotation Period of Comet 41P/Tuttle-Giacobini-Kresák" by Schleicher, Knight, et al. is now in press at AJ, while "Properties of the Bare Nucleus of Comet 96P/Machholz 1" by Eisner, Knight, et al. has been submitted to AJ.

11.10.18 We made the first determination of the rotation period of 46P/Wirtanen this apparition (8.9 hr). The official CBET requires a subscription, but an animation of our images can be seen here.

8.1.18 We finally got around to finishing the paper on C/2007 N3 Lulin. Congratulations to Allison Bair on her first first-author paper!

6.7.18 My proposal to ISSI for a team on interstellar object 1I/`Oumuamua was selected! The team website will eventually appear here.

6.1.18 We were the first to recover comet 46P/Wirtanen this apparition, observing it with DCT on May 8 at an airmass of ~5! Here is the MPEC and the recovery image

2.15.18 I wrote a short article for the LSST Solar System Science Collaboration about why I’m excited about what LSST will do for comet science.

1.19.18 AAS Nova highlighted our recent paper on 1I/'Oumuamua. I also gave a talk on 'Oumuamua at this week's Astronomy on Tap.

1.10.18 Our Nature paper on Comet 41P/Tuttle-Giacobini-Kresak is now out.

11.23.17 Sky and Telescope covered our group's ultra-fast results on the interstellar asteroid (ApJL, submitted).

10.18.17 Our DPS presentation on the unprecedented change in rotation period of comet 41P/Tuttle-Giacobini-Kresak got some press.

9.20.17 Three papers were all recently accepted and appeared on arXiv: "The Rotation and Other Properties of Comet 49P/Arend-Rigaux, 1984-2012" by Eisner et al. (a UMD student who worked with me during 2016-2017), "Gemini and Lowell Observations of 67P/Churyumov-Gerasimenko During the Rosetta Mission" by Knight et al., and "The Main Belt Comets and Ice in the Solar System" by Snodgrass et al.

6.6.17 The journal for the Royal Society meeting I helped organize last year is now online. Also, we have another CBET announcing that 41P/T-G-K's apparent period continues to increase at a surprisingly fast rate!

3.29.17 My collaborators and I have had two recent CBETs on 41P/Tuttle-Giacobini-Kresak. We determined its apparent period in the first, then discovered the apparent period is changing rapidly in the second! [Subscription required]

2.13.17 I was interviewed for BBC Four "The Sky at Night" episode "Telescope Takeover". Streaming is only available in the UK, but a screenshot is here thanks to Geraint Jones.

11.10.16 "SOHO Comets: 20-Years and 3,000 Objects Later" by Battams and Knight has been accepted and is available on arXiv.

10.14.16 The Editorial Board of the AAS journals selected my paper with Man-To Hui as a "significant development in planetary science research."

10.2.16 "The extremely low activity comet 209P/LINEAR during its extraordinary close approach in 2014" has now been published.

7.12.16 "SOHO Comets: 20-Years and 3,000 Objects Later" by Battams and Knight has been submitted to Philsophical Transactions A (the journal for the Royal Society).

5.17.16 The recent papers on 322P/SOHO 1 and 209P/LINEAR have both been accepted. New Scientist wrote a very nice article about 322P.

4.4.16 Two papers were recently submitted: "Comet 322P/SOHO 1: The smallest-perihelion distance asteroid?" by Knight et al. and "The extremely low activity comet 209P/LINEAR during its extraordinary close approach in 2014." by Schleicher and Knight.

2.18.16 Phil Plait covered our work on 2016 BA14!

2.15.16 Mike Kelley, Silvia Protopapa, and I discovered cometary activity on 2016 BA14 which has an historic close flyby of Earth next month! While I'm housekeeping, here are several other papers to which I contributed that are now available online: [Snodgrass et al.] [Kelley et al.] [Samarasinha et al.] [Zubko et al.] [Bemporad et al.]

11.1.15 I have moved to the University of Maryland. I am porting the website over but it needs some updates so bear with me.

10.5.15 "Gone in a Blaze of Glory: the Demise of Comet C/2015 D1 (SOHO)" by Hui et al. was accepted by ApJ and is available on arXiv

8.14.15 My Gemini observations were featured in articles by ESA and Gemini about Rosetta. Also, our paper "Comet C/2012 S1 (ISON) coma composition at ~4 au from HST observations" by Zubko et al. was accepted by PSS.

7.28.15 I was named a NASA Planetary Science Division Early Career Fellow!

5.26.15 Our team made the first ever ground-based detection of a sunskirting object, P/1999 R1 SOHO, using the VLT. Follow up observations have been awarded with VLT and Spitzer to help us determine if this is a comet or an asteroid. [MPEC]

5.13.15 "A Further Investigation of Apparent Periodicities and the Rotational State of Comet 103P/Hartley 2 from Combined Coma Morphology and Lightcurve Datasets" by Knight et al. in now in press and available on arXiv.

3.20.15 "A Further Investigation of Apparent Periodicities and the Rotational State of Comet 103P/Hartley 2 from Combined Coma Morphology and Lightcurve Datasets" by Knight et al. was submitted to AJ.

3.4.15 "Results from the Worldwide Coma Morphology Campaign for Comet ISON (C/2012 S1)" by Samarasinha et al. was submitted to Planetary and Space Sciences.

2.24.15 Our proposal for a Royal Society meeting on "Cometary science after Rosetta" was approved! The meeting will be held in London in June 2016.

1.13.15 I was interviewed for an article on C/2014 Q2 Lovejoy for NPR's Science Friday.

11.18.14 Gemini issued a press release featuring our observations of Rosetta's target comet 67P/Churyumov-Gerasimenko.

10.6.14 "Observations of Comet ISON (C/2012 S1) from Lowell Observatory" by Knight and Schleicher has been accepted and is now on arXiv.

8.14.14 I wrote a short answer for "Ask ASTRO" in this month's Astronomy Magazine.

7.31.14 "Observations of Comet ISON (C/2012 S1) from Lowell Observatory" by Knight and Schleicher has been submitted to AJ.

7.15.14 Asteroid Matthewknight (25053) was named in my honor!

6.2.14 I am now in IMDB!

4.28.14 My ProjectASTRO partner teacher (Rennie Watson) and I were featured in an article in the current issue of ASP's Mercury magazine. You must be a member of the ASP to read the full article.

2.20.14 "Preliminary Analysis of SOHO/STEREO Observations of Sungrazing Comet ISON (C/2012 S1) Around Perihelion" is now published. I am also quoted in today's Nature in article about Comet ISON.

1.2.14 "Preliminary Analysis of SOHO/STEREO Observations of Sungrazing Comet ISON (C/2012 S1) Around Perihelion" by Knight and Battams has been submitted to ApJL.

12.12.13 It has been a busy last few weeks. Some highlights:

  • I am featured in several TV programs about Comet ISON. Previews for Discovery Science and BBC are online. I'm still looking for links for the NHK (Japan) and Darlow Smithson (airing on either PBS or National Geographic) programs that also filmed me.
  • I was interviewed for more news articles on Comet ISON than I could keep up with. A few highlights were Wall Street Journal, CBS, and BBC, and Sky and Telescope.
  • My photometry of Comet ISON was published on CBET 3731

11.25.13 I'll be doing an Ask Me Anything on Reddit tomorrow (November 26) at 9:00 PM EST with a few colleagues. Check us out!

10.29.13 A podcast of my interview with "The Naked Scientists" is now available. I have also been blogging about Comet ISON at the CIOC website. My most recent post is featured as a guest blog by the Planetary Society.

10.1.13 My article "The Science of Comets" is the cover story in the November 2013 issue of Astronomy Magazine which is out on news stands today.

9.13.13 "Will Comet ISON (C/2012 S1) Survive Perihelion?" [arXiv] and "The Nucleus of Comet 10P/Tempel 2 in 2013 and Consequences Regarding Its Rotational State: Early Science from the Discovery Channel Telescope" [arXiv] have both been accepted for publication.

8.27.13 Several papers that have been in the pipeline have all been finished in the last couple of weeks:

  • "Sunskirting Comets Discovered with the LASCO Coronagraphs Over the Decade 1996-2008" by Lamy et al. is now [in press]
  • "Will Comet ISON (C/2012 S1) Survive Perihelion?" by Knight and Walsh has been submitted to ApJL
  • "The Nucleus of Comet 10P/Tempel 2 in 2013 and Consequences Regarding Its Rotational State: Early Science from the Discovery Channel Telescope" by Schleicher, Knight, and Levine has been submitted to AJ
  • "Hubble Space Telescope Pre-Perihelion ACS/WFC Imaging Polarimetry of Comet ISON (C/2012 S1) at 3.81 AU" by Hines et al. has been submitted to ApJL

8.7.13 ISON is keeping me happily busy. Here are a few highlights:


7.8.13 The official NASA Comet ISON Campaign website is now live. I will be blogging about ISON there from time to time, and am also maintaining this plot of ISON's brightness.

5.30.13 HST Cycle 21 notifications came out today and both of my ISON proposals were approved! These will greatly expand on the Cycle 20 DDT proposals we were awarded for imaging, spectroscopy, and polarization. Publications for the DDT programs are in prep now. Also, a talk I gave recently on Comet ISON is posted on NASA's website.

4.29.13 CBET 3496 [subscription required] has preliminary results from our HST observations of Comet ISON. STScI also issued a press release. It has been picked up by many other places.

3.29.13 I'm quoted in a press release about Swift observations of Comet ISON. I was also asked about the red comet in Game of Thrones for a fun story at Universe Today.

3.15.13 I was interviewed for yet another Science@NASA video [text]. It's a good time to be a comet scientist!

2.20.13 Another round of batch updates:

  • I was interviewed for another Science@NASA article. This one is about Comet Pan-STARRS (C/2011 L4). It's also available as video and parts of it have been republished all over.
  • Here are some fun photos from my ProjectASTRO class on making a comet. Thanks to Karen Watson for taking the photos and making the powerpoint.
  • The Icarus special issue on Stardust/EPOXI is finally out, so these papers finally have references.

1.23.13 It's been busy so here are a few belated updates:

  • I was interviewed for a story on Comet ISON(C/2012 S1) for Science@NASA. It's also available as video and has been republished around the world.
  • I got quick set of images of 274P/Tombaugh-Tenagra so Lowell could remind people that Clyde Tombaugh did more than just discover Pluto!
  • "Chandra ACIS-S imaging spectroscopy of anomalously faint X-ray emission from Comet 103P/Hartley 2 during the EPOXI encounter" by Lisse et al. is now in press.
  • I wrote a short response to a reader's question in the December 2012 [subscription required to read the whole response] issue of Astronomy Magazine.

9.14.12 My paper "A Quarter-Century of Observations of Comet 10P/Tempel 2 at Lowell Observatory: Continued Spin-Down, Coma Morphology, Production Rates, and Numerical Modeling" has been accepted by AJ. Preprint is here.

6.7.12 My paper "The Highly Unusual Outgassing of Comet 103P/Hartley 2 from Narrowband Photometry and Imaging of the Coma" has been accepted by Icarus. Preprint is here.

2.17.12 My paper "The Highly Unusual Outgassing of Comet 103P/Hartley 2 from Narrowband Photometry and Imaging of the Coma" has been submitted to the Icarus EPOXI special issue. Also, "Observational and Dynamical Characterization of Main-Belt Comet P/2010 R2 (La Sagra)" by Hsieh et al. has been accepted by AJ.

1.19.12 Yet more sungrazing comets in the news! I was interviewed about a new paper on C/2011 N3 (SOHO) for Scientific American.

1.13.12 More Lovejoy news here and in video form. Check me out at the 2:19 mark in the video!

12.21.11 In case you missed it, Lovejoy survived! I was interviewed for this Science@NASA article and wrote a blog post for Lowell. Stay tuned for more updates.

12.14.11 The most spectacular Kreutz comet of my lifetime was recently discovered (C/2011 W3 Lovejoy). I have been contributing some preliminary analysis to this excellent blog by Karl Battams (NRL).

10.4.11 Results from my EPSC-DPS talk on Hartley 2 were mentioned in a press release from the meeting (complete with figure).

9.29.11 I helped obtain some calibration data for Henry Hsieh's paper "Observational and Dynamical Characterization of Main-Belt Comet P/2010 R2 (La Sagra)" which now has been posted to astro-ph.

6.19.11 An image from my Hartley 2 paper is on the cover of the June 2011 issue of The Astronomical Journal.

5.17.11 "EPOXI: Comet 103P/Hartley 2 Observations from a Worldwide Campaign" (Meech et al. 2011) has now been published online here.

5.4.11 "CN Morphology Studies of Comet 103P/Hartley 2" has now been published online here.

3.30.11 My paper "CN Morphology Studies of Comet 103P/Hartley 2" was accepted by the Astronomical Journal. Pre-print is available on [astro-ph].

1.24.11 Here is a good article about a recent "storm" of sungrazing comets in which I was interviewed. This got picked up by a lot of other websites too!

12.7.10 "The Increasing Rotation Period of Comet 10P/Tempel 2" has now been published online here.

11.11.10 Additional results from Hartley 2 as well as our results reported on 10.22.10 appeared on IAUC 9175 (subscription required).

10.22.10 New results for Comet 103P/Hartley 2: we determined the pole orientation and tentative location of the northern jet (assuming a principal axis rotation) and discovered a southern jet. This appears on CBET 2512 (subscription required) and will appear on an IAUC shortly.

9.16.10 My paper "The Increasing Rotation Period of Comet 10P/Tempel 2" (Knight, Farnham, Schleicher, and Schwieterman) was accepted by the Astronomical Journal. Pre-print is available on astro-ph.

8.20.10 We determined the rotation period of 103P/Hartley 2 is 16.6+/-0.5 hr using CN narrowband imaging August 13-17, 2010. This appears on IAUC 9163 and CBET 2418 (subscriptions required).

7.20.10 My proposal "Studies of Sungrazing Comets Observed by SOHO and STEREO" was selected for funding by NASA PMDAP. [PDF of abstracts]

4.21.10 SOHO has recovered the periodic Marsden comet 1999 J6 = 2004 V9 = 2010 H3 (MPEC 2010-H37, CBET 2256, IAUC 9138 [passwords may be required]). I have made a page comparing the photometry on all three apparitions.

3.30.10 Archived SOHO comet images and photometry are (finally) showing up on ADS.

3.1.10 My article on Comet Lulin in the Lowell Observer is now available as a PDF.

1.6.10 My thesis paper was accepted by the Astronomical Journal. Preprint is here.

11.2.09 I helped obtain observations of Mercury in 2007 which are published here.

10.7.09 Some stories about our ongoing research are here (Lulin), here (Lulin), and here (Tempel 2).

6.24.09 I finished in 6th place in the Baseball Prospectus Idol competition. All of my articles are here.

5.31.09 Not quite astronomy, but I'm a finalist for a baseball writing competition. You can read my articles here, here, and here.

3.7.09 We determined the rotation period of Comet Lulin (C/2007 N3) is about 42 hours from 11 nights of imaging at Anderson Mesa. The IAUC is available here (subscription required). Email me if you'd like to see a movie.

12.11.08 Finally got around to moving the webpage from Maryland to Lowell.

10.30.08 My thesis is now available as a PDF. Email me if you would like a hard copy. Here is my new email address:

1.20.08 I will be doing a postdoc at Lowell Observatory with Dave Schleicher.

Observations of 9P/Tempel 1 during Deep Impact paper is out in Icarus.

Cyanogen Jets and the Rotation State of Comet Machholz (C/2004 Q2) is out in the Astronomical Journal.