The use of radar to study near-earth asteroids has long been a common practice among astronomers. This method allows to determine the form of space rocks, and sometimes to find unknown satellites. But comets fall under the scope of the radar to less common. This is understandable. In the end, equal spans of comets is not so frequent event. Until 2017, only six of the comets were analyzed using radar. This week, the list had expanded to seven. On 11 February, the comet 45p/Honda-Mrkos-Pajdusakova passed at a distance of 12 million kilometers from Earth. Such an opportunity not to be missed.
The above animation is based on the results of observations 45r Observatory Arecibo. As you can see, the comet has gentlewoman form, such as Churyumov-Gerasimenko: two parts connected by the isthmus. Its diameter (the largest along the axis) is 1.3 km, the rotation period is 7.6 hours.
And so the comet looks like through a telescope. Its characteristic green color is caused by emission of diatomic carbon.