These images of the 45P Honda-Mrkos-Pajdušáková comet nucleus were generated from the radar observations obtained over a two-hour period, on 12 February 2017, with the Arecibo (Puerto Rico) radio telescope. The comet was moving 12.4 million kilometers from Earth. The nucleus measures nearly 1.3 km in its largest dimension and it turns on itself in 7.6 hours. These images seem to show that the 45P Honda-Mrkos-Pajdušáková nucleus consists of two lobes, such as that of the comet 67P Churyumov-Gerasimenko.
Credits: NAIC-Arecibo / NSF

Discovered in 1948 , the comet 45P Honda-Mrkos-Pajdušáková is a periodic comet that travels in an elliptical orbit around the Sun in nearly 5.26 years. It therefore returns regularly to our sky and is one of the stars that professional astronomers and amateurs observe and photograph with their instruments. Its orbit never brings it very close to the Sun – it has passed more than 80 million kilometers from it on December 31 last – so that its activity remains moderate and it is never a very bright star in the sky night. This time, 45P Honda-Mrkos-Pajdušáková approached our planet as it gradually moved away from the Sun, and by the chance of the conjugation of its own movement with that of the Earth, it rose to 12 , 4 million kilometers from us on February 11, nearly 32 times the Earth-Moon distance. It may sound like a lot, but in terms of astronomical distances, it’s pretty close. Its brightness has not become exceptional for all that – magnitude 7 at best, so not visible without optical instrument – and its observation has remained particularly delicate for amateurs because this close passage took place during a full moon, while our satellite Natural light illuminated the celestial vault and hid the less brilliant stars. Some experienced observers, however, have managed to spot 45P Honda-Mrkos-Pajdušáková with optical instruments and some experienced photographers have disseminated images of this cotton ball a few days before its perigee. It may sound like a lot, but in terms of astronomical distances, it’s pretty close. Its brightness has not become exceptional for all that – magnitude 7 at best, so not visible without optical instrument – and its observation has remained particularly delicate for amateurs because this close passage took place during a full moon, while our satellite Natural light illuminated the celestial vault and hid the less brilliant stars. Some experienced observers, however, have managed to spot 45P Honda-Mrkos-Pajdušáková with optical instruments and some experienced photographers have disseminated images of this cotton ball a few days before its perigee. It may sound like a lot, but in terms of astronomical distances, it’s pretty close. Its brightness has not become exceptional for all that – magnitude 7 at best, so not visible without optical instrument – and its observation has remained particularly delicate for amateurs because this close passage took place during a full moon, while our satellite Natural light illuminated the celestial vault and hid the less brilliant stars. Some experienced observers, however, have managed to spot 45P Honda-Mrkos-Pajdušáková with optical instruments and some experienced photographers have disseminated images of this cotton ball a few days before its perigee. Its brightness has not become exceptional for all that – magnitude 7 at best, so not visible without optical instrument – and its observation has remained particularly delicate for amateurs because this close passage took place during a full moon, while our satellite Natural light illuminated the celestial vault and hid the less brilliant stars. Some experienced observers, however, have managed to spot 45P Honda-Mrkos-Pajdušáková with optical instruments and some experienced photographers have disseminated images of this cotton ball a few days before its perigee. Its brightness has not become exceptional for all that – magnitude 7 at best, so not visible without optical instrument – and its observation has remained particularly delicate for amateurs because this close passage took place during a full moon, while our satellite Natural light illuminated the celestial vault and hid the less brilliant stars. Some experienced observers, however, have managed to spot 45P Honda-Mrkos-Pajdušáková with optical instruments and some experienced photographers have disseminated images of this cotton ball a few days before its perigee. While our natural satellite illuminated the celestial vault and hid the less brilliant stars. Some experienced observers, however, have managed to spot 45P Honda-Mrkos-Pajdušáková with optical instruments and some experienced photographers have disseminated images of this cotton ball a few days before its perigee. While our natural satellite illuminated the celestial vault and hid the less brilliant stars. Some experienced observers, however, have managed to spot 45P Honda-Mrkos-Pajdušáková with optical instruments and some experienced photographers have disseminated images of this cotton ball a few days before its perigee.