Discard papaya seeds. Peel papaya and chop enough to measure 1/2 cup. Mince enough onion to measure 2 tablespoons and, wearing rubber gloves, mince enough jalapeño (with seeds) to measure 1/2 tablespoon. In a bowl stir together papaya, onion, jalapeño, and remaining ingredients and season with salt. Salsa may be made 1 day ahead and chilled, covered.
