To Hindus, Shakti, the "Great Divine Mother", is the origin of all cosmic energy. She is celebrated in a festival called Navratri, meaning nine nights, and culminates on the 10th day, Dasera. There are five such celebrations each year, and this year Sharada Navratri - often seen as the most important, as Sharad signifies new beginnings - began on Tuesday and will run until Wednesday. During the nine nights, the different manifestations of Shakti are celebrated. Many celebrate three avatars of Shakti - Durga, Lakshmi and Saraswati - for three days each; some worship nine forms, one on each day; and still others worship the Navagraha, or nine cosmic deities that represent the sun, moon, the planets of Mars, Mercury, Jupiter, Venus, Saturn, and the north and south lunar nodes, the points where the moon's path crosses the sun's. Most Hindus keep to a strictly vegetarian diet over Navratri, and one of the foods central to the festival is sundal , a salad made of pulses or grains. In southern India, people visit one another in their homes during Navratri. Many families set up a kolu , an elaborate display of figurines to represent each Hindu god, and invite others to come and enjoy it. It is common for families to make a different sundal on each day of Navratri as offerings to appease the nine graha and, of course, to eat. In Hindu astrology, each graha is associated with a different colour, element, god, gemstone, metal, food and so on, and a sundal is made with the corresponding food. For the sun god, Surya, it is wheat; for the moon god, Chandra, rice; for Mangala or Mars, it is pigeon peas; for Budhan (Mercury), it is mung beans; for Guru (Jupiter) is it chickpeas; for Shukra (Venus), it is kidney beans or white beans; for Shani (Saturn) it is sesame. The north and south lunar nodes, seen as snakes, are offered urad , or black beans and horse gram beans respectively.